# 费茨法则

## 模型

$T = a + b \log_2 \Bigg(1+\frac{D}{W}\Bigg)$

• T 是完成动作的平均时间。（传统的命名方式，会写成MT ，表示运动时间 Movement Time
• a 代表装置（拦截）开始/结束的时间，b 表示该装置本身的速度（斜率）。这些常数可以以测得数据进行直线近似的方式通过实验取得。
• D 是起始位置到目标中心的距离。（传统上来说，研究者多用 A 来表示，意味着运动的振幅 Amplitude
• W 是目标区域在运动维向上的宽度。因为运动的最终点必须落在目标中心 ±W2 以内，所以 W 也可以被认为是被允许的最终位置的容差。

## 参考文献

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• Paul M. Fitts and James R. Peterson (1964). Information capacity of discrete motor responses. Journal of Experimental Psychology, 67(2):103–112, February 1964.
• Stuart K. Card, William K. English, and Betty J. Burr (1978). Evaluation of mouse, rate-controlled isometric joystick, step keys, and text keys for text selection on a CRT. Ergonomics, 21(8):601–613, 1978.
• I. Scott MacKenzie and William A. S. Buxton (1992). Extending Fitts' law to two-dimensional tasks. Proceedings of ACM CHI 1992 Conference on Human Factors in Computing Systems, pp. 219–226. http://doi.acm.org/10.1145/142750.142794
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• Johnny Accot and Shumin Zhai (2003). Refining Fitts' law models for bivariate pointing. Proceedings of ACM CHI 2003 Conference on Human Factors in Computing Systems, pp. 193–200. http://doi.acm.org/10.1145/642611.642646
• Johnny Accot and Shumin Zhai (2002). More than dotting the i's — foundations for crossing-based interfaces. Proceedings of ACM CHI 2002 Conference on Human Factors in Computing Systems, pp. 73–80. http://doi.acm.org/10.1145/503376.503390
• Stuart K. Card, Thomas P. Moran, Allen Newell (1983). The Psychology of Human-Computer Interaction.
• I. Scott MacKenzie (1992). Fitts' law as a research and design tool in human-computer interaction. Human-Computer Interaction, volume 7, 1992, pp. 91–139. http://www.yorku.ca/mack/hci1992.pdf
• Meyer, D. E., Smith, J. E. K., Kornblum, S., Abrams, R. A., & Wright, C. E. (1990). Speed-accuracy tradeoffs in aimed movements: Toward a theory of rapid voluntary action. In M. Jeannerod (Ed.), Attention and performance XIII (pp. 173–226). Hillsdale, NJ: Lawrence Erlbaum. http://www.umich.edu/~bcalab/Meyer_Bibliography.html
• A. T. Welford (1968). Fundamentals of Skill. Methuen, 1968.
• Shumin Zhai (2002). On the Validity of Throughput as a Characteristic of Computer Input, IBM Research Report RJ 10253, 2002, Almaden Research Center, San Jose, California. http://www.almaden.ibm.com/u/zhai/papers/ZhaiIBMReporRJ10253.pdf