Practice Schedules and the Use of Component Skills in Problem Solving

In motor and verbal learning, random practice schedules produce poorer acquisition performance but superior retention relative to blocked practice. We extend this contextual interference effect to the case of learning cognitive procedural skills to be used in problem solving. Subjects in three experiments practiced calculation with Boolean functions. After this acquisition phase, subjects solved problems requiring these procedures. Experiments 1 and 2 demonstrated superior transfer to problem solving for skills acquired under random schedules. In Experiment 3, subjects practiced component skills in a blocked schedule, with one of four tasks-same-different judgment, mental arithmetic, short-term memory, or long-term memory-intervening between trials. For same-different judgments and mental arithmetic, transfer performance was comparable to that found for random schedules in Experiments 1 and 2. This result suggests that the differences depend on processing rather than storage demands of intertrial activity. Implications for theories of problem solving and part-whole transfer are discussed.