Counting Effective Number of Buttons: An Informational Analysis of Input Device Performance
Toru Nakata · 1997
A quantitative method to evaluate theoretical efficiency of input devices is proposed. Using informatics, the method answers effective degrees of freedom in input devices; it evaluates how many buttons are efficiently used for operation. Comparing traditional methods represented by “magical number of seven, ” this method is versatile for general usability tests of any input devices, since the method requires only frequencies of stimuli and responses between machines and users.