Abstract: | Young adults solved a problem in which hobbits and orcs had to be transported across a river. In Expt I, a Part-Whole group of subjects solved the problem starting at a different state in the middle and then were given the entire problem. Comparison with a Control group indicated that the initial practice of the Part-Whole group did not facilitate their later performance on the same problem segment, but did facilitate performance in a different portion of the problem. In Expt II, some subjects were given feedback halfway through the problem that they were on the right track. Results gave some support to the notion that a possible difficulty in the problem is the subject's belief that he must have entered a blind alley in the search space. However, other difficulties were also involved. Inferences from several different dependent performance variables, the transfer results, and subjects' comments consistently suggested that subjects solving this problem needed to undergo a number of cognitive changes (3–4) that was smaller than the minimum number of external moves required to solve the problem (11). |