Random and blocked practice of movement sequences: differential effects on response structure and movement speed.

Three similar six-element key press sequences were practiced under blocked or random practice schedules with acquisition conducted on one day and retention and transfer on the next day. The task required participants to type, as quickly as possible, one of three 6-element sequences as observed on a computer monitor. In blocked practice, participants completed all practice in one repeated sequence before the next repeated sequence was introduced. In random acquisition practice, the three repeated sequences were randomly presented to the participants. The data suggest that random practice results in participants adopting a uniform response structure, while blocked practice allows participants to exploit unique sequential aspects of the individual tasks. This finding suggests that random practice may not be as effective as blocked practice when one of the tasks being practiced together can be optimized through the development of a unique response structure.