Motor programming during practice conditions high and low in contextual interference

Random practice has been reported to demand greater time for movement prepa ration during acquisition than blocked practice. The present study revealed that this could be attributed to a more complete engagement of the motor p rogramming process during random practice. This cost, however, was localize d to the motor programming subprocess that S. T. Klapp (1995) associated wi th organizing the internal structure of a movement chunk rather than an alt ernative subprocess responsible for organizing movement chunks into the cor rect serial order. The more thorough employment of motor programming during acquisition by random practice participants resulted in a more efficient u se of this planning operation during retention, as well as more accurate mo vement reproduction. These data support the claim that practice conditions high in contextual interference support improvements in both movement prepa ration and memory strength.