Prior experience and complex procedures.

The role of prior knowledge in learning complex procedures was investigated in a transfer task in which subjects learned two related procedures in sequence. In Experiment 1, we manipulated the conceptual and structural similarity between the two procedures; in Experiment 2, we manipulated whether the order of the steps within subprocedures was the same or different during training and transfer, or whether the order of the subprocedures was the same or different. The results lead us to hypothesize that transfer in complex procedures is mediated primarily by a memory for specific steps rather than by conceptual understanding or problem solving. In particular, we were able to model the results precisely on the assumption that subjects use superficial similarity to retrieve the sequences of steps needed to perform segments of the procedure.