loosely speaking, I think there's a limit on finger actions per unit time, so if you're spending more per letter, you're getting a lower WPM as an example, Mat

loosely speaking, I think there's a limit on finger actions per unit time, so if you're spending more per letter, you're getting a lower WPM as an example, Matias' one-hand keyboard, in which half of the characters cost an extra keypress, had people getting up to 75% of their normal qwerty WPM [1] I've never seen any study of a chording keyboard doing more than 70 WPM without a steno style multiple character output system [1]: http://edgarmatias.com/papers/ic93/ http://edgarmatias.com/papers/ic93/