On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer...

26
On Testing for Biases in Peer Review Ivan Stelmakh, Nihar Shah and Aarti Singh

Transcript of On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer...

Page 1: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

On Testing for Biases in Peer Review

Ivan Stelmakh, Nihar Shah and Aarti Singh

Page 2: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Lady Justice. Court of Final Appeal, Hong Kong

Lady Justice. Supreme Court, Moscow

Double-Blind vs Single-Blind

Blank, 1991; Seeber & Bacchelli, 2017; Snodgrass, 2006; Largent & Snodgrass, 2016; Okike et al., 2016; Budden et al., 2008; Webb et al., 2008; Hill & Provost, 2003

Page 3: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Background

• In 2017 Tomkins, Zhang and Heavlin conducted a remarkable semi-randomized controlled trial during the peer review for the WSDM conference to test for biases in single-blind peer review

• They found biases in favour of papers authored by Researchers from top universitiesResearchers from top companiesFamous authors

• WSDM switched to the double-blind setup in 2018, but many CS theory conferences still use single-blind peer review

The focus of this work is on principled design of the methods to test for biases within conference peer review

Page 4: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

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ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

wj ∈ {−1,1}

- protected attribute Equals 1 if paper’s authors belong to a category of interest.

wPapers

Question of interestAre reviewers in SB setup biased against or in favour of papers from the category of interest?

If we are interested in gender biases, then if a paper has a female lead author and

otherwise

w = 1

w = − 1Reviewers

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Accept

Reject

Reviewers in SB setup observe the protected attribute

In this talk we assume that there is only one protected attribute

Problem setup and notation

Reviewers in DB setup do not observe the protected attribute

Page 5: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Naive approach

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

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Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

A Voting-Based System for Ethical Decision Making

Ritesh Noothigattu

Machine Learning Dept.CMU

Snehalkumar ‘Neil’ S. Gaikwad

The Media LabMIT

Edmond Awad

The Media LabMIT

Sohan Dsouza

The Media LabMIT

Iyad Rahwan

The Media LabMIT

Pradeep Ravikumar

Machine Learning Dept.CMU

Ariel D. Procaccia

Computer Science Dept.CMU

Abstract

We present a general approach to automating ethical deci-sions, drawing on machine learning and computational socialchoice. In a nutshell, we propose to learn a model of societalpreferences, and, when faced with a specific ethical dilemmaat runtime, efficiently aggregate those preferences to identifya desirable choice. We provide a concrete algorithm that in-stantiates our approach; some of its crucial steps are informedby a new theory of swap-dominance efficient voting rules. Fi-nally, we implement and evaluate a system for ethical deci-sion making in the autonomous vehicle domain, using prefer-ence data collected from 1.3 million people through the MoralMachine website.

1 Introduction

The problem of ethical decision making, which has longbeen a grand challenge for AI (Wallach and Allen 2008),has recently caught the public imagination. Perhaps its best-known manifestation is a modern variant of the classic trol-

ley problem (Jarvis Thomson 1985): An autonomous vehiclehas a brake failure, leading to an accident with inevitablytragic consequences; due to the vehicle’s superior percep-tion and computation capabilities, it can make an informeddecision. Should it stay its course and hit a wall, killing itsthree passengers, one of whom is a young girl? Or swerveand kill a male athlete and his dog, who are crossing thestreet on a red light? A notable paper by Bonnefon, Shariff,and Rahwan (2016) has shed some light on how people ad-dress such questions, and even former US President BarackObama has weighed in.1

Arguably the main obstacle to automating ethical deci-sions is the lack of a formal specification of ground-truthethical principles, which have been the subject of debatefor centuries among ethicists and moral philosophers (Rawls1971; Williams 1986). In their work on fairness in machinelearning, Dwork et al. (2012) concede that, when ground-truth ethical principles are not available, we must use an “ap-proximation as agreed upon by society.” But how can societyagree on the ground truth — or an approximation thereof —when even ethicists cannot?

We submit that decision making can, in fact, be auto-mated, even in the absence of such ground-truth principles,

1https://www.wired.com/2016/10/president-obama-mit-joi-ito-interview/

by aggregating people’s opinions on ethical dilemmas. Thisview is foreshadowed by recent position papers by Greeneet al. (2016) and Conitzer et al. (2017), who suggest thatthe field of computational social choice (Brandt et al. 2016),which deals with algorithms for aggregating individual pref-erences towards collective decisions, may provide tools forethical decision making. In particular, Conitzer et al. raisethe possibility of “letting our models of multiple people’smoral values vote over the relevant alternatives.”

We take these ideas a step further by proposing and im-plementing a concrete approach for ethical decision makingbased on computational social choice, which, we believe, isquite practical. In addition to serving as a foundation for in-corporating future ground-truth ethical and legal principles,it could even provide crucial preliminary guidance on someof the questions faced by ethicists. Our approach consists offour steps:

I Data collection: Ask human voters to compare pairs of al-ternatives (say a few dozen per voter). In the autonomousvehicle domain, an alternative is determined by a vectorof features such as the number of victims and their gender,age, health — even species!

II Learning: Use the pairwise comparisons to learn a modelof the preferences of each voter over all possible alterna-tives.

III Summarization: Combine the individual models into asingle model, which approximately captures the collec-tive preferences of all voters over all possible alternatives.

IV Aggregation: At runtime, when encountering an ethicaldilemma involving a specific subset of alternatives, usethe summary model to deduce the preferences of all vot-ers over this particular subset, and apply a voting rule toaggregate these preferences into a collective decision. Inthe autonomous vehicle domain, the selected alternativeis the outcome that society (as represented by the voterswhose preferences were elicited in Step I) views as theleast catastrophic among the grim options the vehicle cur-rently faces. Note that this step is only applied when allother options have been exhausted, i.e., all technical waysof avoiding the dilemma in the first place have failed, andall legal constraints that may dictate what to do have alsofailed.

w = − 1 w = 1

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1

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iv:1

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6v3

[cs.G

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5

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

A Voting-Based System for Ethical Decision Making

Ritesh Noothigattu

Machine Learning Dept.CMU

Snehalkumar ‘Neil’ S. Gaikwad

The Media LabMIT

Edmond Awad

The Media LabMIT

Sohan Dsouza

The Media LabMIT

Iyad Rahwan

The Media LabMIT

Pradeep Ravikumar

Machine Learning Dept.CMU

Ariel D. Procaccia

Computer Science Dept.CMU

Abstract

We present a general approach to automating ethical deci-sions, drawing on machine learning and computational socialchoice. In a nutshell, we propose to learn a model of societalpreferences, and, when faced with a specific ethical dilemmaat runtime, efficiently aggregate those preferences to identifya desirable choice. We provide a concrete algorithm that in-stantiates our approach; some of its crucial steps are informedby a new theory of swap-dominance efficient voting rules. Fi-nally, we implement and evaluate a system for ethical deci-sion making in the autonomous vehicle domain, using prefer-ence data collected from 1.3 million people through the MoralMachine website.

1 Introduction

The problem of ethical decision making, which has longbeen a grand challenge for AI (Wallach and Allen 2008),has recently caught the public imagination. Perhaps its best-known manifestation is a modern variant of the classic trol-

ley problem (Jarvis Thomson 1985): An autonomous vehiclehas a brake failure, leading to an accident with inevitablytragic consequences; due to the vehicle’s superior percep-tion and computation capabilities, it can make an informeddecision. Should it stay its course and hit a wall, killing itsthree passengers, one of whom is a young girl? Or swerveand kill a male athlete and his dog, who are crossing thestreet on a red light? A notable paper by Bonnefon, Shariff,and Rahwan (2016) has shed some light on how people ad-dress such questions, and even former US President BarackObama has weighed in.1

Arguably the main obstacle to automating ethical deci-sions is the lack of a formal specification of ground-truthethical principles, which have been the subject of debatefor centuries among ethicists and moral philosophers (Rawls1971; Williams 1986). In their work on fairness in machinelearning, Dwork et al. (2012) concede that, when ground-truth ethical principles are not available, we must use an “ap-proximation as agreed upon by society.” But how can societyagree on the ground truth — or an approximation thereof —when even ethicists cannot?

We submit that decision making can, in fact, be auto-mated, even in the absence of such ground-truth principles,

1https://www.wired.com/2016/10/president-obama-mit-joi-ito-interview/

by aggregating people’s opinions on ethical dilemmas. Thisview is foreshadowed by recent position papers by Greeneet al. (2016) and Conitzer et al. (2017), who suggest thatthe field of computational social choice (Brandt et al. 2016),which deals with algorithms for aggregating individual pref-erences towards collective decisions, may provide tools forethical decision making. In particular, Conitzer et al. raisethe possibility of “letting our models of multiple people’smoral values vote over the relevant alternatives.”

We take these ideas a step further by proposing and im-plementing a concrete approach for ethical decision makingbased on computational social choice, which, we believe, isquite practical. In addition to serving as a foundation for in-corporating future ground-truth ethical and legal principles,it could even provide crucial preliminary guidance on someof the questions faced by ethicists. Our approach consists offour steps:

I Data collection: Ask human voters to compare pairs of al-ternatives (say a few dozen per voter). In the autonomousvehicle domain, an alternative is determined by a vectorof features such as the number of victims and their gender,age, health — even species!

II Learning: Use the pairwise comparisons to learn a modelof the preferences of each voter over all possible alterna-tives.

III Summarization: Combine the individual models into asingle model, which approximately captures the collec-tive preferences of all voters over all possible alternatives.

IV Aggregation: At runtime, when encountering an ethicaldilemma involving a specific subset of alternatives, usethe summary model to deduce the preferences of all vot-ers over this particular subset, and apply a voting rule toaggregate these preferences into a collective decision. Inthe autonomous vehicle domain, the selected alternativeis the outcome that society (as represented by the voterswhose preferences were elicited in Step I) views as theleast catastrophic among the grim options the vehicle cur-rently faces. Note that this step is only applied when allother options have been exhausted, i.e., all technical waysof avoiding the dilemma in the first place have failed, andall legal constraints that may dictate what to do have alsofailed.

7 positive reviews18 negative reviews

20 positive reviews5 negative reviews

Can we conclude that there is a bias in favour of papers with ?w = 1

NO! Think about category of interest being Nobel laureates.

Page 6: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Hypothesis testing framework

Null hypothesis (absence of bias)

knowledge of the protected attribute does not change reviewers attitude to the paper

Alternative hypothesis (presence of bias)

H0 :

H1 :knowledge of the protected attribute makes reviewers more harsh to papers with and more lenient to papers with

wj = − 1wj = 1

Type-I errorClaiming presence of bias when the bias is absent

Type-II errorClaiming absence of bias when the bias is present

For a given our goal is to design a test that provably keeps Type-I error rate below and subject to this has low Type-II error

αα

Data: reviewers decisions and papers authorship information

Page 7: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Past approach: parametrization of objectivity

Tomkins, Zhang and Heavlin, 2017

Page 8: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1

arX

iv:1

502.

0569

6v3

[cs.G

T] 7

Sep

201

5

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

A Voting-Based System for Ethical Decision Making

Ritesh Noothigattu

Machine Learning Dept.CMU

Snehalkumar ‘Neil’ S. Gaikwad

The Media LabMIT

Edmond Awad

The Media LabMIT

Sohan Dsouza

The Media LabMIT

Iyad Rahwan

The Media LabMIT

Pradeep Ravikumar

Machine Learning Dept.CMU

Ariel D. Procaccia

Computer Science Dept.CMU

Abstract

We present a general approach to automating ethical deci-sions, drawing on machine learning and computational socialchoice. In a nutshell, we propose to learn a model of societalpreferences, and, when faced with a specific ethical dilemmaat runtime, efficiently aggregate those preferences to identifya desirable choice. We provide a concrete algorithm that in-stantiates our approach; some of its crucial steps are informedby a new theory of swap-dominance efficient voting rules. Fi-nally, we implement and evaluate a system for ethical deci-sion making in the autonomous vehicle domain, using prefer-ence data collected from 1.3 million people through the MoralMachine website.

1 Introduction

The problem of ethical decision making, which has longbeen a grand challenge for AI (Wallach and Allen 2008),has recently caught the public imagination. Perhaps its best-known manifestation is a modern variant of the classic trol-

ley problem (Jarvis Thomson 1985): An autonomous vehiclehas a brake failure, leading to an accident with inevitablytragic consequences; due to the vehicle’s superior percep-tion and computation capabilities, it can make an informeddecision. Should it stay its course and hit a wall, killing itsthree passengers, one of whom is a young girl? Or swerveand kill a male athlete and his dog, who are crossing thestreet on a red light? A notable paper by Bonnefon, Shariff,and Rahwan (2016) has shed some light on how people ad-dress such questions, and even former US President BarackObama has weighed in.1

Arguably the main obstacle to automating ethical deci-sions is the lack of a formal specification of ground-truthethical principles, which have been the subject of debatefor centuries among ethicists and moral philosophers (Rawls1971; Williams 1986). In their work on fairness in machinelearning, Dwork et al. (2012) concede that, when ground-truth ethical principles are not available, we must use an “ap-proximation as agreed upon by society.” But how can societyagree on the ground truth — or an approximation thereof —when even ethicists cannot?

We submit that decision making can, in fact, be auto-mated, even in the absence of such ground-truth principles,

1https://www.wired.com/2016/10/president-obama-mit-joi-ito-interview/

by aggregating people’s opinions on ethical dilemmas. Thisview is foreshadowed by recent position papers by Greeneet al. (2016) and Conitzer et al. (2017), who suggest thatthe field of computational social choice (Brandt et al. 2016),which deals with algorithms for aggregating individual pref-erences towards collective decisions, may provide tools forethical decision making. In particular, Conitzer et al. raisethe possibility of “letting our models of multiple people’smoral values vote over the relevant alternatives.”

We take these ideas a step further by proposing and im-plementing a concrete approach for ethical decision makingbased on computational social choice, which, we believe, isquite practical. In addition to serving as a foundation for in-corporating future ground-truth ethical and legal principles,it could even provide crucial preliminary guidance on someof the questions faced by ethicists. Our approach consists offour steps:

I Data collection: Ask human voters to compare pairs of al-ternatives (say a few dozen per voter). In the autonomousvehicle domain, an alternative is determined by a vectorof features such as the number of victims and their gender,age, health — even species!

II Learning: Use the pairwise comparisons to learn a modelof the preferences of each voter over all possible alterna-tives.

III Summarization: Combine the individual models into asingle model, which approximately captures the collec-tive preferences of all voters over all possible alternatives.

IV Aggregation: At runtime, when encountering an ethicaldilemma involving a specific subset of alternatives, usethe summary model to deduce the preferences of all vot-ers over this particular subset, and apply a voting rule toaggregate these preferences into a collective decision. Inthe autonomous vehicle domain, the selected alternativeis the outcome that society (as represented by the voterswhose preferences were elicited in Step I) views as theleast catastrophic among the grim options the vehicle cur-rently faces. Note that this step is only applied when allother options have been exhausted, i.e., all technical waysof avoiding the dilemma in the first place have failed, andall legal constraints that may dictate what to do have alsofailed.

SB condition

DB condition

Reviewers are allocated to conditions uniformly at random

For simplicity, assume tha t each paper i s assigned to 1 SB and 1 DB reviewer

Allocation Assignment (any algorithm)

Setup of the experiment

Page 9: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Objective score model

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Each paper has unknown parameter that represents a quality of the paper.

Double blind estimate

DB reviewers estimate paper quality

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

q1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

qq• DB reviewers do not have access to protected attribute • Estimated quality is not biasedq

Testing procedure

Page 10: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Testing procedure

- probability that reviewer recommends acceptance of paper in SB setup π(sb)ij ∈ [0,1] i j

- protected attribute wj ∈ {−1,1}

Logistic model for bias

unknown coefficients to be estimated from data

logπ(sb)

ij

1 − π(sb)ij

= β0 + β1qj + β2wj (1)

β0, β1, β2 −

∀i, j

• Use DB reviewers to estimate for each paper and use plugin estimates in (1)

• Fit observed accept/reject decisions of SB reviewers into logistic model

• Use Wald test at the level to test if

qj j qj

α β2 = 0

Outline of the Tomkins et al. test

H0 : β2 = 0

H1 : β2 ≠ 0

Null hypothesis (absence of bias)

Alternative hypothesis (presence of bias)

Page 11: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Negative results

Page 12: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Key ingredientRecall that for some categories of authors it is natural to expect that their papers have above average qualities (the Nobel laureates example)

Formally, this intuition can be expressed as a non-zero correlation between and .w q

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1

arX

iv:1

502.

0569

6v3

[cs.G

T] 7

Sep

201

5

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

A Voting-Based System for Ethical Decision Making

Ritesh Noothigattu

Machine Learning Dept.CMU

Snehalkumar ‘Neil’ S. Gaikwad

The Media LabMIT

Edmond Awad

The Media LabMIT

Sohan Dsouza

The Media LabMIT

Iyad Rahwan

The Media LabMIT

Pradeep Ravikumar

Machine Learning Dept.CMU

Ariel D. Procaccia

Computer Science Dept.CMU

Abstract

We present a general approach to automating ethical deci-sions, drawing on machine learning and computational socialchoice. In a nutshell, we propose to learn a model of societalpreferences, and, when faced with a specific ethical dilemmaat runtime, efficiently aggregate those preferences to identifya desirable choice. We provide a concrete algorithm that in-stantiates our approach; some of its crucial steps are informedby a new theory of swap-dominance efficient voting rules. Fi-nally, we implement and evaluate a system for ethical deci-sion making in the autonomous vehicle domain, using prefer-ence data collected from 1.3 million people through the MoralMachine website.

1 Introduction

The problem of ethical decision making, which has longbeen a grand challenge for AI (Wallach and Allen 2008),has recently caught the public imagination. Perhaps its best-known manifestation is a modern variant of the classic trol-

ley problem (Jarvis Thomson 1985): An autonomous vehiclehas a brake failure, leading to an accident with inevitablytragic consequences; due to the vehicle’s superior percep-tion and computation capabilities, it can make an informeddecision. Should it stay its course and hit a wall, killing itsthree passengers, one of whom is a young girl? Or swerveand kill a male athlete and his dog, who are crossing thestreet on a red light? A notable paper by Bonnefon, Shariff,and Rahwan (2016) has shed some light on how people ad-dress such questions, and even former US President BarackObama has weighed in.1

Arguably the main obstacle to automating ethical deci-sions is the lack of a formal specification of ground-truthethical principles, which have been the subject of debatefor centuries among ethicists and moral philosophers (Rawls1971; Williams 1986). In their work on fairness in machinelearning, Dwork et al. (2012) concede that, when ground-truth ethical principles are not available, we must use an “ap-proximation as agreed upon by society.” But how can societyagree on the ground truth — or an approximation thereof —when even ethicists cannot?

We submit that decision making can, in fact, be auto-mated, even in the absence of such ground-truth principles,

1https://www.wired.com/2016/10/president-obama-mit-joi-ito-interview/

by aggregating people’s opinions on ethical dilemmas. Thisview is foreshadowed by recent position papers by Greeneet al. (2016) and Conitzer et al. (2017), who suggest thatthe field of computational social choice (Brandt et al. 2016),which deals with algorithms for aggregating individual pref-erences towards collective decisions, may provide tools forethical decision making. In particular, Conitzer et al. raisethe possibility of “letting our models of multiple people’smoral values vote over the relevant alternatives.”

We take these ideas a step further by proposing and im-plementing a concrete approach for ethical decision makingbased on computational social choice, which, we believe, isquite practical. In addition to serving as a foundation for in-corporating future ground-truth ethical and legal principles,it could even provide crucial preliminary guidance on someof the questions faced by ethicists. Our approach consists offour steps:

I Data collection: Ask human voters to compare pairs of al-ternatives (say a few dozen per voter). In the autonomousvehicle domain, an alternative is determined by a vectorof features such as the number of victims and their gender,age, health — even species!

II Learning: Use the pairwise comparisons to learn a modelof the preferences of each voter over all possible alterna-tives.

III Summarization: Combine the individual models into asingle model, which approximately captures the collec-tive preferences of all voters over all possible alternatives.

IV Aggregation: At runtime, when encountering an ethicaldilemma involving a specific subset of alternatives, usethe summary model to deduce the preferences of all vot-ers over this particular subset, and apply a voting rule toaggregate these preferences into a collective decision. Inthe autonomous vehicle domain, the selected alternativeis the outcome that society (as represented by the voterswhose preferences were elicited in Step I) views as theleast catastrophic among the grim options the vehicle cur-rently faces. Note that this step is only applied when allother options have been exhausted, i.e., all technical waysof avoiding the dilemma in the first place have failed, andall legal constraints that may dictate what to do have alsofailed.

q = 10 q = 9 q = 6 q = 2

cor(q, w) > 0

Correlation itself doesn’t cause issues, but we identify several conditions where it can be significantly harmful

Page 13: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Reviewers’ noise

●●

●●

200 400 600 800 10000.0

0.2

0.4

0.6

0.8

1.0

Number of papers

Type−I

erro

r● Previous work

Our test

Reviewers are noisy and hence should be seen as a noisy estimate of In presence of correlations, the noise in covariate measurement may undermine Type-I error guarantees of the Tomkins et al. test

qj qj

Comparison of Type-I error rates when DB reviewers are noisy. Valid test must have Type-I error below α = 0.05

Observe that the issue exacerbates as sample size grows!

Page 14: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Model mismatchReasonable violation of the parametric model may break Type-I error guarantees of the test from the past work

200 400 600 800 10000.0

0.2

0.4

0.6

0.8

1.0

Number of papers

Type−I

erro

r

Comparison of Type-I error rates under violation of parametric model. Valid test must have Type-I error below

α = 0.05

Page 15: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Miscalibration

0 20 40 60 80 1000.0

0.2

0.4

0.6

0.8

1.0

Reviewer load

Type−I

erro

r

Parametric model assumes that reviews given by the same reviewer to different papers are independent. In practice, this assumption may be violated due to spurious correlations introduced by reviewers’ miscalibration

Comparison of Type-I error rates for specific pattern of reviewers’ miscalibration. Valid test must have Type-I error below α = 0.05

Wang & Shah, 2018

Page 16: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

BiddingIf SB reviewers observe protected attributes during the bidding state and DB reviewers do not, the testing for biases in decisions is hard

Comparison of Type-I error rates for specific pattern of reviewers’ bidding. Valid test must have Type-I error below α = 0.05

Non−blind Blind

Type−I

erro

r rat

e0.

00.

20.

40.

60.

81.

0

Bidding in SB condition

Previous workDisagreement test

Page 17: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Non-random assignmentUnder the experimental setup of Tomkins et al., if reviewers are assigned to papers using popular TPMS assignment algorithm, then controlling Type-I error rate is hard

Comparison of Type-I error rates for specific pattern of similarity matrix. Valid test must have Type-I error below α = 0.05

Observe that even our robust test is unable to control for the Type-I error when assignment of papers to reviewers is not random.

Non−blind Blind

Type−I

erro

r0.

00.

20.

40.

60.

81.

0

Bidding in SB condition

Previous workDisagreement test

TPMS Random

Type−I

erro

r rat

e0.

00.

20.

40.

60.

81.

0

Assignment type

Page 18: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Our approach: deparametrization of subjectivity

Page 19: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1

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5

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

A Voting-Based System for Ethical Decision Making

Ritesh Noothigattu

Machine Learning Dept.CMU

Snehalkumar ‘Neil’ S. Gaikwad

The Media LabMIT

Edmond Awad

The Media LabMIT

Sohan Dsouza

The Media LabMIT

Iyad Rahwan

The Media LabMIT

Pradeep Ravikumar

Machine Learning Dept.CMU

Ariel D. Procaccia

Computer Science Dept.CMU

Abstract

We present a general approach to automating ethical deci-sions, drawing on machine learning and computational socialchoice. In a nutshell, we propose to learn a model of societalpreferences, and, when faced with a specific ethical dilemmaat runtime, efficiently aggregate those preferences to identifya desirable choice. We provide a concrete algorithm that in-stantiates our approach; some of its crucial steps are informedby a new theory of swap-dominance efficient voting rules. Fi-nally, we implement and evaluate a system for ethical deci-sion making in the autonomous vehicle domain, using prefer-ence data collected from 1.3 million people through the MoralMachine website.

1 Introduction

The problem of ethical decision making, which has longbeen a grand challenge for AI (Wallach and Allen 2008),has recently caught the public imagination. Perhaps its best-known manifestation is a modern variant of the classic trol-

ley problem (Jarvis Thomson 1985): An autonomous vehiclehas a brake failure, leading to an accident with inevitablytragic consequences; due to the vehicle’s superior percep-tion and computation capabilities, it can make an informeddecision. Should it stay its course and hit a wall, killing itsthree passengers, one of whom is a young girl? Or swerveand kill a male athlete and his dog, who are crossing thestreet on a red light? A notable paper by Bonnefon, Shariff,and Rahwan (2016) has shed some light on how people ad-dress such questions, and even former US President BarackObama has weighed in.1

Arguably the main obstacle to automating ethical deci-sions is the lack of a formal specification of ground-truthethical principles, which have been the subject of debatefor centuries among ethicists and moral philosophers (Rawls1971; Williams 1986). In their work on fairness in machinelearning, Dwork et al. (2012) concede that, when ground-truth ethical principles are not available, we must use an “ap-proximation as agreed upon by society.” But how can societyagree on the ground truth — or an approximation thereof —when even ethicists cannot?

We submit that decision making can, in fact, be auto-mated, even in the absence of such ground-truth principles,

1https://www.wired.com/2016/10/president-obama-mit-joi-ito-interview/

by aggregating people’s opinions on ethical dilemmas. Thisview is foreshadowed by recent position papers by Greeneet al. (2016) and Conitzer et al. (2017), who suggest thatthe field of computational social choice (Brandt et al. 2016),which deals with algorithms for aggregating individual pref-erences towards collective decisions, may provide tools forethical decision making. In particular, Conitzer et al. raisethe possibility of “letting our models of multiple people’smoral values vote over the relevant alternatives.”

We take these ideas a step further by proposing and im-plementing a concrete approach for ethical decision makingbased on computational social choice, which, we believe, isquite practical. In addition to serving as a foundation for in-corporating future ground-truth ethical and legal principles,it could even provide crucial preliminary guidance on someof the questions faced by ethicists. Our approach consists offour steps:

I Data collection: Ask human voters to compare pairs of al-ternatives (say a few dozen per voter). In the autonomousvehicle domain, an alternative is determined by a vectorof features such as the number of victims and their gender,age, health — even species!

II Learning: Use the pairwise comparisons to learn a modelof the preferences of each voter over all possible alterna-tives.

III Summarization: Combine the individual models into asingle model, which approximately captures the collec-tive preferences of all voters over all possible alternatives.

IV Aggregation: At runtime, when encountering an ethicaldilemma involving a specific subset of alternatives, usethe summary model to deduce the preferences of all vot-ers over this particular subset, and apply a voting rule toaggregate these preferences into a collective decision. Inthe autonomous vehicle domain, the selected alternativeis the outcome that society (as represented by the voterswhose preferences were elicited in Step I) views as theleast catastrophic among the grim options the vehicle cur-rently faces. Note that this step is only applied when allother options have been exhausted, i.e., all technical waysof avoiding the dilemma in the first place have failed, andall legal constraints that may dictate what to do have alsofailed.

SB condition

DB condition

Reviewers are allocated to conditions uniformly at random

For simplicity, assume tha t each paper i s assigned to 1 SB and 1 DB reviewer

Allocation Random Assignment

Setup of the experiment

For today’s talk only.

Page 20: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

- probability that reviewer recommends acceptance of paper in DB setup π(db)ij ∈ [0,1] i j

- probability that reviewer recommends acceptance of paper in SB setup π(sb)ij ∈ [0,1] i j

Our formulation

Absence of bias. There is no difference in behaviour of SB and DB reviewers

H0 : π(sb)ij = π(db)

ij ∀i, j

Presence of bias. Each reviewer is more harsh (resp. lenient) to papers with (resp. ) in SB condition than in DB conditionw = 1 w = − 1

H1 :π(sb)

ij ≤ π(db)ij if wj = 1

π(sb)ij ≥ π(db)

ij if wj = − 1

• Subjective score model. We do not assume existence of true underlying scores and hence allow for subjectivity

• Non-parametric model. We do not assume any parametric relationship that describes reviewers’ behaviour

Our formulation generalizes the formulation of the past work

At least one inequality is strict

Page 21: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Testing procedure. IntuitionH0 : π(sb)

ij = π(db)ij ∀i, j

In each pair reviewers d i s a g r e e i n t h e i r decisions

pairsn

{How many accepts do y o u e x p e c t i n S B condition?

How many accepts do y o u e x p e c t i n D B condition?

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1ar

Xiv

:150

2.05

696v

3 [c

s.GT]

7 S

ep 2

015

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

w = 1

w = 1

w = 1

Assume that the bias is absent

We expect approximately equal number of accepts

Page 22: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Testing procedure. Intuition

In each pair reviewers d i s a g r e e i n t h e i r decisions

pairsn

{How many accepts do y o u e x p e c t i n S B condition?

How many accepts do y o u e x p e c t i n D B condition?

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

What is the language in this image?

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

(a)

Latin Thai Tamil Japanese Hebrew Chinese Russian Hindi

Select ALL options that could be the language in this image

(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

1ar

Xiv

:150

2.05

696v

3 [c

s.GT]

7 S

ep 2

015

Iterative Learning for Reliable Crowdsourcing

Systems

David R. Karger Sewoong Oh Devavrat Shah

Department of Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

Cambridge, MA 02139{karger,swoh,devavrat}@mit.edu

Abstract

Crowdsourcing systems, in which tasks are electronically distributed to numerous“information piece-workers”, have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification,data entry, optical character recognition, recommendation, and proofreading. Be-cause these low-paid workers can be unreliable, nearly all crowdsourcers mustdevise schemes to increase confidence in their answers, typically by assigningeach task multiple times and combining the answers in some way such as ma-jority voting. In this paper, we consider a general model of such crowdsourcingtasks, and pose the problem of minimizing the total price (i.e., number of task as-signments) that must be paid to achieve a target overall reliability. We give a newalgorithm for deciding which tasks to assign to which workers and for inferringcorrect answers from the workers’ answers. We show that our algorithm signifi-cantly outperforms majority voting and, in fact, is asymptotically optimal throughcomparison to an oracle that knows the reliability of every worker.

1 Introduction

Background. Crowdsourcing systems have emerged as an effective paradigm for human-poweredproblem solving and are now in widespread use for large-scale data-processing tasks such as imageclassification, video annotation, form data entry, optical character recognition, translation, recom-mendation, and proofreading. Crowdsourcing systems such as Amazon Mechanical Turk1 providea market where a “taskmaster” can submit batches of small tasks to be completed for a small fee byany worker choosing to pick them up. For example, a worker may be able to earn a few cents by indi-cating which images from a set of 30 are suitable for children (one of the benefits of crowdsourcingis its applicability to such highly subjective questions).

Since typical crowdsourced tasks are tedious and the reward is small, errors are common even amongworkers who make an effort. At the extreme, some workers are “spammers”, submitting arbitraryanswers independent of the question in order to collect their fee. Thus, all crowdsourcers needstrategies to ensure the reliability of answers. Because the worker crowd is large, anonymous, andtransient, it is generally difficult to build up a trust relationship with particular workers.2 It is alsodifficult to condition payment on correct answers, as the correct answer may never truly be knownand delaying payment can annoy workers and make it harder to recruit them for your future tasks.Instead, most crowdsourcers resort to redundancy, giving each task to multiple workers, payingthem all irrespective of their answers, and aggregating the results by some method such as majority

1http://www.mturk.com2For certain high-value tasks, crowdsourcers can use entrance exams to “prequalify” workers and block

spammers, but this increases the cost and still provides no guarantee that the prequalified workers will try hard.

1

1434

ISSN 1064-2269, Journal of Communications Technology and Electronics, 2017, Vol. 62, No. 12, pp. 1434–1447. © Pleiades Publishing, Inc., 2017.Original Russian Text © V.V. V’yugin, I.A. Stel’makh, V.G. Trunov, 2016, published in Informatsionnye Protsessy, 2016, Vol. 16, No. 3, pp. 260–280.

Adaptive Algorithm of Tracking the Best Experts TrajectoryV. V. V’yugin*, I. A. Stel’makh, and V. G. Trunov

Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, 127051 Russia*e-mail: [email protected]

Received September 26, 2016

Abstract—The problem of decision theoretic online learning is discussed. There is the set of methods, experts,and algorithms capable of making solutions (or predictions) and suffering losses due to the inaccuracy of theirsolutions. An adaptive algorithm whereby expert solutions are aggregated and sustained losses not exceeding(to a certain quantity called a regret) those of the best combination of experts distributed over the predictioninterval is proposed. The algorithm is constructed using the Fixed-Share method combined with the Ada-Hedge algorithm used to exponentially weight expert solutions. The regret of the proposed algorithm is esti-mated. In the context of the given approach, there are no any stochastic assumptions about an initial datasource and the boundedness of losses. The results of numerical experiments concerning the mixing of expertsolutions with the help of the proposed algorithm are presented. The strategies of games on financial markets,which were suggested in our previous papers, play the role of expert strategies.

Keywords: prediction with expert advice, online decision making, AdaHedge algorithm, Fixed-Share algo-rithm, regret, adaptive learning parameterDOI: 10.1134/S1064226917120117

1. INTRODUCTIONIn this paper, the methods and algorithms belong-

ing to the theory of prediction with expert advice arediscussed. The given area of machine learning wasintroduced in [7, 9, 10] (the basic monograph on thistheme is [4]). An analogous approach was used in [14].

In each game round (step) t = 1, 2, …, T, the algo-rithm takes the certain decision, namely, the loss dis-tribution vector

where

is chosen for all i. Afterward, experts i = 1, …, N arriveat their solutions. As a result, they sustain losses , i =1, …, N. The algorithm losses are defined as

During the game, the cumulative losses of experts and

the algorithm are acquired: and ,

respectively. In classical study [5], the Hedge(η) algorithm rely-

ing on exponential weighting of expert solutions, the

goal of which was to make solution such that, at anyround T, its losses

were less than those of the best expert,

plus some small learning error (regret). More accu-rately, the algorithm is intended for minimizing theregret

A whole number of algorithms for solving this problemwas presented in [4]. An important parameter of thealgorithm based on exponentially weighted expertsolutions is the so-called learning rate η, which deter-mines the convergence rate of algorithmic solutions tooptimal ones.

The modern version of the Hedge algorithm makesuse of the adaptive (variable) learning parameter η =ηt. The corresponding AdaHedge (AH) algorithm wasreported in [8]. Let and be thesmallest and largest losses of experts at step t, respec-

tively. It is assumed that . In

addition, let st = – and ST = max{s1, …, sT}. In

( )= 1, ,,..., ,t t N tw w w

=

= ≥∑ , ,1

1 and 0N

i t i t

i

w w

itl

=

= ∑ ,1

.N

it i t t

i

h w l

=

= ∑1

Ti iT t

t

L l=

= ∑1

T

t

t

H h

=

= ∑1

,T

T t

t

H h

≤ ≤=

1* min iT T

i NL L

= − *.T T TR H L

− = min it t

il l + = max i

t ti

l l

+ + − −

= =

= =∑ ∑

1 1

,T T

T t T t

t t

L l L l

+tl

−tl

MATHEMATICAL MODELSAND COMPUTATIONAL METHODS

w = 1

w = 1

w = 1

Assume that the bias is present

We expect more accepts from DB reviewers

H1 :π(sb)

ij ≤ π(db)ij if wj = 1

π(sb)ij ≥ π(db)

ij if wj = − 1

Page 23: On Testing for Biases in Peer Revie · 2019. 10. 27. · to test for biases in single-blind peer review • They found biases in favour of papers authored by Researchers from top

Testing procedure

Disagreement test

• Find a set of triples (SB reviewer, DB reviewer, Paper) such thatEach reviewer appears in at most one tripleThere are ‘enough’ papers with and

• Condition on triples where reviewers disagree in their decisions• Run permutation test at the level to look for ‘trends’ in the remaining triples

w = − 1 w = 1

α

Approval Voting and Incentives in Crowdsourcing

Nihar B. Shah Dengyong Zhou Yuval PeresUC Berkeley Microsoft Research Microsoft Research

[email protected] [email protected] [email protected]

Abstract

The growing need for labeled training data has made crowdsourcing an important part of machinelearning. The quality of crowdsourced labels is, however, adversely affected by three factors: (1) theworkers are not experts; (2) the incentives of the workers are not aligned with those of the requesters; and(3) the interface does not allow workers to convey their knowledge accurately, by forcing them to makea single choice among a set of options. In this paper, we address these issues by introducing approvalvoting to utilize the expertise of workers who have partial knowledge of the true answer, and coupling itwith a (“strictly proper”) incentive-compatible compensation mechanism. We show rigorous theoreticalguarantees of optimality of our mechanism together with a simple axiomatic characterization. We alsoconduct preliminary empirical studies on Amazon Mechanical Turk which validate our approach.

1 Introduction

In the big data era, with the ever increasing complexity of machine learning models such as deep learning,the demand for large amounts of labeled data is growing at an unprecedented scale. A primary means oflabel collection is crowdsourcing, through commercial web services like Amazon Mechanical Turk wherecrowdsourcing workers or annotators perform tasks in exchange for monetary payments. Unfortunately,the data obtained via crowdsourcing is typically highly erroneous (Kazai et al., 2011; Vuurens et al., 2011;Wais et al., 2010) due to the lack of expertise of workers, lack of appropriate incentives, and often thelack of an appropriate interface for the workers to express their knowledge. Several statistical aggregationmethods (Dawid and Skene, 1979; Whitehill et al., 2009; Raykar et al., 2010; Karger et al., 2011; Liu et al.,

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(a)

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(b)

Figure 1: Illustration of a task with (a) the standard single selection interface, and (b) an approval-votinginterface.

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We disagree on this paper!

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Main Result

Informal theoremUnder our formulation of the bias testing problem, if the assignment of reviewers to papers is performed at random, the disagreement test controls for the Type-I error rate at any given level and has non-trivial power.α ∈ (0,1)

In the full version of the paper we omit the requirement of the random assignment, thereby ensuring that the test can be run irrespective of what the assignment algorithm is used

Remark

Power — ability to detect bias when it is present

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Power of the test

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rDB reviewers are noisy

Al l assumptions of the previous work are satisfied

Synthetic simulations. Higher values are better. Bias is present in both cases. Error bars are too small to be visible.

Power — ability to detect bias when it is present

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Outline• Past approaches to test for biases in peer review are at risk of being unreliable

under plausible violations of strong assumptions

• We design the Disagreement test that provably controls for the Type-I error rate under significantly weaker assumptions

More in the full paper

• General case of more than one protected attribute

• Generalization of the bias testing problem in case SB condition itself may change the behaviour of reviewers even under absence of bias

• New experimental procedure that allows for any assignment algorithm to be used