Objectives and hypotheses Wim Buysse Ric Coe RUFORUM 28 November 2006 Research Methods Group.

Objectives and hypotheses

Wim BuysseRic Coe

RUFORUM 28 November 2006

Research Methods Group

Part 1. The importance of setting objectives


Where do you want to be in life 10 years from now ?


Where does my organisation/firm wants to be 10 years from now ?


Keeney, R.L.1992Value-Focused Thinking: A Path to Creative Decision making. Cambridge, MA: Harvard University Press.


A real life example


• You have a job in Nairobi• Your wife is offered a job in Kisumu• Alternatives: we live apart or ‘she’ can’t work• What are your values – you want to live in the

same town, and you both want to work• Focusing on values drives you to create

alternatives (as opposed to choosing among existing alternatives)

• Innovate – You convince your company you can start up a new office in Kisumu

Setting objectives


Setting objectives (in life/in management of an organisation) provides structure, purposiveness, focus, meaning and enables you to measure progress in the right direction or the lack of it.

Setting objectives in a research project


The hypothetico-deductive method


• induction = inferring a general law or principle from the observation of particular instances

• deduction = inferring from generals to particulars

Research = learning to solve problems


So far it has been a soup


"Science consists of both knowledge and the process by which this knowledge is created, research. Although research succeeds by building and testing better theories, the process involves constructs, concepts, and activities that are not themselves predictive. Non-predictive constructs serve science as logical devices, memory aids, inspirational prods, incentives to thought, political opinions, personal ideals, half-formed notions, odd beliefs, and unexpressed ideas. These elements are not 'bad' or unscientific. They form a prescientific soup from which each scientist draws inspiration and from which the disciplined human mind has constructed modern science."

Peters, Robert Henry (1991) A critique for ecology. Cambridge University Press, Cambridge, UK. 366 pp. ISBN 0 521 39588 7 - p. 21

synthetic or private phase

Synthetic or private phase


•Logic•Knowledge of discipline•Creativity•Imagination•Lateral thinking

The importance of setting objectives = structure


The objectives drive the rest of the study.

• your hypotheses• the kind of study that needs to be

done (experiment, survey, ....)• the treatments that have to be

compared• the population to be sampled• the data to be collected• the formal statistical analysis

needed• ....

analyticor public phase

Analytic or public phase


Ability to extrapolate findings beyond a given location and to make some kind of prediction rather than just a description.

Communicate findings => ‘public’ phase

When? For ALL types of research!

• Biophysical, social, economic, policy…• Lab, field, landscape,…• Participatory,…• Strategic, applied, adaptive• …

• Maybe NOT for activities with local ‘development’ outcomes only


Part 2. The confusion


The confusion


• research questions• overall objectives• specific objectives• one hypothesis• several hypotheses• null-hypothesis• hypothesis testing

• and their order

Basically


Objectives– Why you are doing the work

• Hypotheses– Elements of theory you will test– A testable hunch

• (Research questions)– Overall statement of what you are going to

research

Part 3. ‘Good’ objectives


Objectives

• The overall aim • Must be…

– Clear – Complete– Relevant– Reasonable– Capable of being met by the activities (experiments

and surveys)– NOT ‘To compare treatments’ or ‘To compare

populations’…


Example Objective

"To evaluate 4 improved mango varieties".– Which varieties?– Under what conditions (location,

management) are they to be evaluated?– What criteria will be used to evaluate them? – Linked to what problem solving strategy? – What is the science behind this?


"To determine whether the survival and growth rates, during the first two years, of improved mango varieties (Kent, Van Dyke, Tommy Atkins and Sensation) can be brought up to the level of the local variety by using a higher level of management ( addition of manure and water), when these trees are grown in crop fields of the coffee zone of Embu, Kenya"

Better?


A characterisation of the research process

observe

reflect

generalise

plan

Question theory

Formulate modifications

Design studies

Collect data

Interpret

Update theory


Hypotheses

• Modifications of, additions to, or new theory…

• …that generate alternative predictions…

• …that can be compared with data

• Usually stated as a ‘rule’ or a cause-effect relationship.


Example

Addition of manure and water will increase initial growth and survival of new mango varieties …

because…

they promote vigorous root growth.First part:

•Easy to test

•Not clear what it adds to understanding

Second part

•Harder to test

•Maybe adds much more to theory

Hypotheses should be…

• Useful– Fill a critical gap in the problem solving

process– Allow you to do something you cannot

currently do

Ocimum populations vary in the level of active ingredients

Variation in active ingredients in different Ocimum populations is large enough to exploit pharmacologically

OR

Highland populations of Ocimum have active ingredient profiles similar enough to coast populations that they may also be used as substitutes

Active ingredients in Ocimum are a plant response to stress so will be found in higher concentrations in more stressed environments

• Logical– Based on current understanding and theory

(social, economic as well as biophysical)– Avoid alchemy

Deep rooted legumes can increase soil N in sandy soils if the dry season water table is shallow.

Fallowing with Myfavourite treespecies will increase soil N on sandy soils.


• Testable– Logically– Logistically

Soils can regenerate after serious erosion if left undisturbed for long enough

Changes in soil fertility following forest clearance are caused by changes in soil bacteria populations.


• How many…? Where…? What is the difference…?– often local description only

• How…? Why…?– potential to

• generalise to other situations• contribute to the body of scientific knowledge• generate abstraction


Most useful hypotheses

• Include ‘How?’ or ‘Why?’

Adoptability of improved fallow varies by gender

Women find improved fallow less adoptable than men because of labour shortages, low priority for maize production and lack of information


Expressing the hypothesis

• Words– may get long winded

• Simple models

Soil CPlant C

litter

roots

decomposition

erosion


• Empty tables or graphs

Forest Annual monocrops

Soil quality

Time since conversion


Time since conversion

Forest

Annual monocrops


Part 4. The pitfalls


Common problems

• Status of hypothesis already known– researcher not sufficiently familiar with current theory– hypothesis is trivial (‘Species differ…’)

• Study is just a realisation of a phenomenon in a new environment – without hypotheses of why it may be different in that new

environment

• Hypothesis does not take problem forward– Apply the ‘So what?’ test.

• Hypothesis stated as statistical null hypothesis– does not direct design or test– can always be demonstrated with a poor study– often known to be false


Common problems

• ‘I am doing an exploratory study. I don’t what to pre-empt results or restrict what I might find by writing hypotheses’– …but then you don’t even know what to

measure!– Hypotheses are there but vague and unstated– Writing them down, however complex, can

only help.


In practice• Expect to cycle through problem-objectives-hypotheses several times until it all makes sense• Do ‘thought experiments’. Write down (in tables or graphs) the

sort of results which would confirm or refute your hypotheses• Share your problem-objectives-hypotheses statements with as

many people who may give constructive help as possible.• Don’t be afraid to state hypotheses that challenge common

views – but only if you present a strong case.• Recognise that the finished product of problem-objectives-

hypotheses-design-results-conclusion you read in a paper rarely started out that way as the research was conceived and designed

• Read books on scientific method


Part 5. The toolbox


Talk

• Feedback

• Constructive criticism

Take initiative.


Question

Decision Protocol 2.0 USDA Forest Service


Problem and goal tree

DFID. 2002. Tools for development handbook. A handbook for those engaged in development activity.


Advanced ideas


Underutilised idea:

• Pre-testing hypotheses with quantitative models


Outcome Impact on design

1. No relevant model Add model building to objectives

2. Hypothesis not confirmed by model

(a) model assumptions are unrealistic

Add model refinement to objectives

(b) model assumptions are realistic

Examine your assumptions, modify them and produce revised hypothesis3. Hypothesis

confirmed by the model.

Hypothesis is a consequence of current knowledge. There may be more useful objectives for field trials.

Read

Chapter 5 and 6


Read

Chapter 3.2


Read

Ford, E. David (2000) Scientific Method for Ecological Research.

Cambridge University Press. 564 pp.

ISBN 0 521 66973 1


Peters, Robert Henry (1991) A critique for ecology. Cambridge University Press, Cambridge, UK. 366 pp. ISBN 0 521 39588 7

Objectives and hypotheses Wim Buysse Ric Coe RUFORUM 28 November 2006 Research Methods Group.

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