1. Topic: Fitts' Law Lawrence Fyfe CPSC 681

2. Fitts' Law Formula: ID (index of difficulty) = log 2 (D/W +1) Soukoreff R.W., MacKenzie I.S., 2004. Towards a standard for pointing device evaluation, perspectives on 27 years of Fitts' law research in HCI. International Journal of Human Computer Studies, 61 (6), pp. 751-789.

3. Paul Fitts' Experiment: Fitts, P.M., 1954. The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology 47 (6), 381–391. Reciprocal Tapping Apparatus

4. Tapping Results: Fitts, P.M., 1954. The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology 47 (6), 381–391.

5. Fitts' Law and HCI: Card, S.K., English, W.K., Burr, B.J., 1978. Evaluation of mouse, rate-controlled isometric joystick, step keys, and text keys for text selection on a CRT. Ergonomics 21, 601–613.

6. Distance Results: Card, S.K., English, W.K., Burr, B.J., 1978. Evaluation of mouse, rate-controlled isometric joystick, step keys, and text keys for text selection on a CRT. Ergonomics 21, 601–613.

7. Card, S.K., English, W.K., Burr, B.J., 1978. Evaluation of mouse, rate-controlled isometric joystick, step keys, and text keys for text selection on a CRT. Ergonomics 21, 601–613. Target Size Results:

8. Problems: http://particletree.com/features/visualizing-fittss-law/

9. Multidirectional Tapping: Soukoreff R.W., MacKenzie I.S., 2004. Towards a standard for pointing device evaluation, perspectives on 27 years of Fitts' law research in HCI. International Journal of Human Computer Studies, 61 (6), pp. 751-789.

10. User Interface Guidelines: http://msdn.microsoft.com/en-us/library/ms993291.aspx 1. The blue line represents the boundary of the clickable region. 2. The example on the right shows how a larger clickable space is easier to target. 3. An example of small click targets in close proximity, making it difficult to target them easily.

11. Usability: http://www.codinghorror.com/blog/archives/000642.html Fitts' Law and Infinite Width

12. Questions?