S scanned a list of random letters looking for 1 to 5 target letters, which were read to him just before the list was presented. His scanning rate was estimated from a graph of the time required to find a target at different positions in the list. The more targets S was seeking, the more slowly he scanned. The time spent processing each non-target letter in the list increased in direct proportion to the number of targets for which S was searching.

The S was shown a series of 40 S-letter anagrams. The first 20 anagrams could all be solved by rearranging their letters in the same order, the next 10 followed a different order, and the last 10 followed a 3rd rule. As S solved the anagrams, his eye movements were photographed. After the whole series had been presented, S was asked whether he had noticed any pattern in the anagrams. Those Ss who discovered the rules developed distinctive eye-movement patterns: they looked at the letters of the anagram in the order that they appeared in the solution word, and the solution was achieved with just S fixations, 1 on each letter. When the rule that solved the anagrams was changed, the fixation pattern also changed to follow the new rule. This oculomotor response may be regarded as the behavioral counterpart of a "mental set" to perceive the letters in the order of the rule.

No abstract

The >S"' s task was to list all the 4-letter words he could make up from a set of 5-10 different letters. Responses occurred rapidly at first and then more slowly as S exhausted his store of words. When S had more letters to work with, he could generate a greater total number of words, but took longer to produce any given fraction of them. Thus with 5 letters, 5 found 80% of his limit of 8 words in less than 5 min., whereas with 10 letters, S took more than 15 min. to find 80% of his limit of 43 words. The results were analyzed in terms of a model that compared the retrieval of information from memory to a search process.