1 / 20

Exploring Human Performance Theories in HCI: Fitts' Law and Beyond

Dive into empirical laws and dynamic models used in HCI theories, focusing on Fitts' Law for task performance predictions and trajectory-based tasks. Discover how to leverage Fitts' Law to enhance user interface design. Explore innovative ways to improve targeting and navigation in interaction design. Uncover the principles behind steering laws and optimizing performance through ID/MT calculations. Learn how to apply Fitts' Law to enhance user experience. Expand your knowledge of HCI principles for effective design practices.

vanmatre
Download Presentation

Exploring Human Performance Theories in HCI: Fitts' Law and Beyond

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CS160 Discussion Session - 7 Jingtao Wang 10/17/2008

  2. Administrivia • Midterm Review on next Friday 10/24/2008 • No multiple choice, most of the questions will be short Q&As.

  3. Witty Exchange • Professor: “Q6. Why is recognition preferred over recall? [3 points]” • Student: “Why isn’t this test multiple choice? ” • Professor: “Because it’s testing what you know, not helping you fill out the answers… i.e. you’re supposed to have recall.”

  4. Theories of Human Performance • Type of theories and models used in HCI: • Empirical laws • Dynamic models • Explanatory theories When look at low enough level (cognitive / motor),people are the same. can predict performance

  5. Empirical Laws • Quantitative rules that provide predictions • Based on experiments or controlled studies • Sometimes are more “rules of thumb” • Encoded as a quantitative empirical ‘model’, commonly known as a ‘Law’ • Examples: Hick’s Law and Fitts’ Law

  6. W D Example: Pointing Device Evaluation • Real task: interacting with GUI’s • Pointing is fundamental • Experimental task: target acquisition • abstract, elementary, essential (target) (start) D = distance W = target width

  7. Movement Time Index of Difficulty (ID [bits] ) W D Fitts’ Law Paul Fitts, 1954 • Index of Performance (IP ) = ID/MT (bits/s) • Depends on bandwidth and throughput Task difficulty is analogous to information: execution time is interpreted ashuman rate of processing information

  8. IP depends on activity / motor unit * * * * * * * * different way to calculate IP * * * * * * * * * * b = slope IP = 1/b * * * * * * * * * * * * a

  9. 50 years of data Reference: MacKenzie, I. Fitts’ Law as a research and design tool in human computer interaction. Human Computer Interaction, 1992, Vol. 7, pp. 91-139

  10. What does Fitts’ law really model? target width (c) velocity (a) (b) distance

  11. Beyond Pointing: trajectory-based Tasks

  12. D W D/2 D/2 D/N D/N D/N D W From Targets to Tunnels… • 1 goal to pass through: • 2 goals to pass through: • N goals to pass through: •  goals to pass through:

  13. fixed width tunnel: narrowing tunnel: W1 W(x) W2 dx general Steering Law: W(s) ds D c W Steering Law (Accot, 1997)“Beyond Fitts’ Law: Models for trajectory based HCI tasks.”Proceedings of ACM CHI 1997 Conference

  14. Some Results (from Accot, 1997)

  15. How to Leverage Fitts Law to Improve User Interface Design? • Directly changing these two parameters obviously does nothing more than change the size and position of onscreen graphical elements, which are presumably already laid out in a reasonably optimal fashion due in part to the interface designer’s basic appreciation of Fitts’ law. • Prospective Directions • Decrease D • Increase W • Decrease D and Increase W • Leveraging Extra Context Information

  16. Pop-up linear menu Pop-up pie menu Today Sunday Monday Tuesday Wednesday Thursday Friday Saturday Decrease D - 1 Linear Menu vs. Pie Menu

  17. Decrease D - 2 Drag and Pop

  18. Increase W – Dynamically Increaseing the Target Size

  19. Increase W (cursor size) • A Failed attempt – Mac OS X Dock

  20. Increase W – Dynamically Increaseing the Target Size

More Related