Fitts' law shows that movement time is influenced by the combination of movement amplitude and target width, such that movement speed and accuracy are inversely related. This speed-accuracy tradeoff is important because many tasks require both speed and accuracy, as seen when teaching children to hit in tee ball. It also applies to exercise science and can be demonstrated using a tapping test where increasing the distance between targets or decreasing their size results in longer movement times.

1. Fitts’ Law & The Speed-Accuracy
Trade-Off
Stacey Dingus
J.R. Voitelle

2. OUTLINE
• What is Fitts’ Law and the Speed-Accuracy Trade-
Off?
• Why is it important?
• How does it relate to Physical Education and
Exercise Science?
• Limitations
• Examples and Videos
• Demonstration
• References

3. WHAT?
• Fitts’ Law shows that movement time (MT) is
influenced by the combination of movement
amplitude and target width. (Lab 5.2)
• The Speed-Accuracy Trade-Off is the
relationship between speed and accuracy.
When movement speed increases, movement
accuracy decreases.

4. IMPORTANCE
• The speed-accuracy trade-off is important
because some tasks that we perform have
both speed and accuracy performance.
• Example: Swinging a baseball bat

5. Relationship with Phys. Ed.
• The relationship between the speed-accuracy
trade-off and physical education is that when
teaching children to play tee ball, they need to
have speed but also have accuracy. This also
applies to other sports that are taught in
physical education class.

6. Relationship with Exercise Science

7. Limitations
• No Limitations
• The speed-accuracy trade-off can apply to
anything in life. Whether its teaching a sport
or playing on the computer.

8. Fitts’ Tapping Test
Home
A

9. Target Size

10. Distance Between Tagets

11. Fitts’ Law Test
• Speed-Accuracy Trade-Off

12. References
http://www.facebook.com/l.php?u=http%3A%2F%2Fgrants.hhp.coe.uh.edu%2Fcla
yne%2FHistoryofMC%2FKeele1968.pdf&h=424a5
http://web.mac.com/gknoblich/assets/Grosjeanetal2007.pdf
http://www.youtube.com/watch?v=kly2QA1bFc8
http://www.gw.utwente.nl/cpe/medewerkers_cpe/Verwey/Publicaties%20Prof.%2
0Dr.%20Ing.%20Willem%20Verwey/1997_hancock_verwey_bbs.pdf
http://www.humankinetics.com/excerpts/excerpts/the-speed-accuracy-trade-off
http://scholar.lib.vt.edu/theses/available/etd-08062001-
125706/unrestricted/Ch2.pdf
digby.tamu.edu/classes/406/ch9.ppt
Lab 5.2 Worksheet