{Building Blocks

Scientific foundations for Interface Design

HCI Remixed “Chapter 47: A Most Fitting Law”Presented by Sarah Deighan

Gary Olson

Donald Bren Professor of Information& Computer ScienceUniversity of California - Irvine

Emeritus ProfessorUniversity of Michigan

Professor of psychologyInstitute of Psychology, Chinese Academy of Science – Beijing

CHI Academy, ACM SIGCHI, 2003CHI Lifetime Achievement Award, ACM SIGCHI, 2006

Human-Computer Interaction Collaboration

Technology Computer Supported

Cooperative Work Interface Design Intelligent Tools Organizational Issues

Cognitive Science Cognition in its

Social and Physical Settings

Problem-Solving and Reasoning

Communication

Gary OlsonProfessional Interests

Paul M. Fitts

Psychologist,The Ohio State University

Psychologist,University of Michigan

Lieutenant Colonel,US Air Force

President of the Division of Applied Experimental andEngineering Psychology,American Psychological Association

President,Human Factors and Ergonomics Society

Fitts’ Experiment

The rate of performance of all the tasks studied increased uniformly as movement amplitude was decreased and as tolerance limits were extended.Pg 387

Fitts’ Conclusion

MT = a + b log2 ( 2D / W )

MT = Movement Time W = Target Width D = Distance to Targeta & b = empirically determined constants

Fitts’ Law Video

Fitts’ Law

What types of interactions or interfaces are exempt from Fitts’ Law?

Discussion Questions

What do you believe is more useful to the HCI field, the equation or the principle represented?

Discussion Questions

How important or unimportant is it for new interfaces to be assessed with quantitative methods as opposed to only qualitative methods?

Discussion Questions

Do we as the HCI community focus too much on user feedback and qualitative evaluations?

Discussion Questions

Ravin Balakrishnan

Professor & Canada Research ChairUniversity of Toronto

CHI Academy, ACM SIGCHI 2011

Applying Fitts’ law principles to decrease MT by manipulating the variables Distance to the target Target Size Control-Device Gain

Applying Fitts’ Law

Making the target appear on command Pop-up menus Drop-down menus Circle Menus

Bringing items to the cursor temporarily

Drag and Pop

Reducing distance to the target

Taking the cursor to selectable itemsObject Pointing

Providing more than one cursorNinja cursorshttp://youtu.be/l0QM-RPlL8s

Reducing distance to the target

Area Cursors

Point cursor Area Cursor

http://youtu.be/JUBXkD_8ZeQ

Increasing width of the target

Expanding the target

Increasing width of the target

Basic version Single gain setting that the user

must use

Dynamically adjusting gain “Sticky” targets

Manipulating Gain

AB

C

What represents C-D gain in the equation for Fitts’ Law?

Discussion Questions

Do you think that participant results from basic manipulations of C-D gain is a manipulation or reflection of Fitts’ Law?

Discussion Questions

Do any of these interaction techniques discussed actually “beat” Fitts’ Law?

Discussion Questions

Do you believe that Balakrishnan’s analysis of any of these new techniques would have changed if he had been including more qualitative methods?

Discussion Questions

What interaction techniques discussed do you think would be found most and least acceptable?

Discussion Questions

Do you think that we should expend energy in developing more quantitative evaluation techniques?

Discussion Questions

Do you think that HCI as a discipline should be more concerned with “basic” work or should we focus on “applied” work?

Discussion Questions