# 📝Hick’s law

- tags
- § Design Psychology
- source
- Закон Хика, который мы потеряли в интерпретации - Vadym Shliachkov - Medium

The law says that the mean reaction time is linear function of the mean entropy. Entropy growths logarithmically with the number of choices available.

$RT = a + b * log_2 (n + 1)$

where

- $RT$ is reaction time
- $log_2 (n + 1)$ is mean entropy
- $a$ and $b$ are coefficients (should be found empirically for each case)

- Hick’s law is about choice reaction time,
*not decision time*as is commonly thought. - The law presumes that correct answer is known and is not something that should be thought about or discovered. (Subjects undertook a training before running the experiment.)
- The law is not universal. There are many situation when it does not apply.