Fitts's law

A simple line drawing of a target box with a side length of W and distance to it D
Fitts's law: draft of target size W and distance to target D

Fitts's law (often cited as Fitts' law) is a predictive model of human movement primarily used in human–computer interaction and ergonomics. The law predicts that the time required to rapidly move to a target area is a function of the ratio between the distance to the target and the width of the target.[1] Fitts's law is used to model the act of pointing, either by physically touching an object with a hand or finger, or virtually, by pointing to an object on a computer monitor using a pointing device. It was initially developed by Paul Fitts.

Fitts's law has been shown to apply under a variety of conditions; with many different limbs (hands, feet,[2] the lower lip,[3] head-mounted sights[4]), manipulanda (input devices),[5] physical environments (including underwater[6]), and user populations (young, old,[7] special educational needs,[8] and drugged participants[9]).

  1. ^ Fitts, Paul M. (June 1954). "The information capacity of the human motor system in controlling the amplitude of movement". Journal of Experimental Psychology. 47 (6): 381–391. doi:10.1037/h0055392. PMID 13174710. S2CID 501599.
  2. ^ Hoffmann, Errol R. (1991). "A comparison of hand and foot movement times". Ergonomics. 34 (4): 397–406. doi:10.1080/00140139108967324. PMID 1860460.
  3. ^ Jose, Marcelo Archajo; Lopes, Roleli (2015). "Human–computer interface controlled by the lip". IEEE Journal of Biomedical and Health Informatics. 19 (1): 302–308. doi:10.1109/JBHI.2014.2305103. PMID 25561451.
  4. ^ So, R. H. Y.; Griffin, M. J. (2000). "Effects of target movement direction cue on head-tracking performance". Ergonomics. 43 (3): 360–376. doi:10.1080/001401300184468. PMID 10755659. S2CID 40311484.
  5. ^ MacKenzie, I. Scott; Sellen, A.; Buxton, W. A. S. (1991). "A comparison of input devices in element pointing and dragging tasks". Proceedings of the SIGCHI Conference on Human Factors in Computing Systems - CHI '91. pp. 161–166. doi:10.1145/108844.108868. ISBN 978-0897913836. S2CID 7637584.
  6. ^ Kerr, R (1973). "Movement time in an underwater environment". Journal of Motor Behavior. 5 (3): 175–178. doi:10.1080/00222895.1973.10734962. PMID 23961747.
  7. ^ Brogmus, G (1991). "Effects of age and sex on speed and accuracy of hand movements: And the refinements they suggest for Fitts's law". Proceedings of the Human Factors Society Annual Meeting. 35 (3): 208–212. doi:10.1177/154193129103500311. S2CID 143675256.
  8. ^ Smits-Engelsman, B. C. M.; Wilson, P. H.; Westenberg, Y.; Duysens, J. (2003). "Fine motor deficiencies in children with developmental coordination disorder and learning disabilities: An underlying open-loop control deficit". Human Movement Science. 22 (4–5): 495–513. doi:10.1016/j.humov.2003.09.006. PMID 14624830.
  9. ^ Kvålseth, T. O. (1977). "Effects of marijuana on human reaction time and motor control". Perceptual and Motor Skills. 45 (3): 935–939. doi:10.2466/pms.1977.45.3.935. PMID 600655. S2CID 39382776.