Effects of practice on a typing-like keying task

Twenty hours of practice on a sequential keying task were administered to determine the mechanisms responsible for practice-related improvement. Sensitivity to varying stimulus probabilities was evident from the earliest stages of practice and did not shift with continued experience. The efficiency of making keystrokes involving overlap of successive finger movements improved more than that for keystrokes with no possibility of overlap, and an index of eye-hand span revealed that with practice subjects expanded their degree of anticipatory preparation. It was suggested that one of the most important things acquired with skill is the ability to execute several processes simultaneously.