Three procedures for improving problem-solving performance by modifying search strategies were investigated. These were: (a) unaided experience, (b) experience plus exposure to strategies described only as a procedural change, and (c) experience plus exposure to strategies that were explicitly described as solution strategies. 10 Ss were tested under each condition on a series of 3-element conjunctive problems monitored by an automatic programming machine called HEPP. It was found that procedure (a), unaided experience, was the least effective technique for developing efficient search strategies. When problems of increased uncertainty were presented to Ss tested under this condition, the group showed a significant loss in problem-solving efficiency. Ss tested under procedure (b) also showed a loss in efficiency on the transfer task although the loss was not as great as that shown by Ss tested under procedure (a). The most effective method for modifying search strategies was procedure (c). Ss in this group changed to a more efficient strategy and were able to use the strategy to solve problems of increased uncertainty with almost no loss in efficiency of performance.
