CONTEXT AND GOODNESS IN A FOCUSING TASK

In a focusing task, people respond positively to one stimulus and negatively to all other stimuli that occur. The task has been called focusing in recognition of the possibility that only the target stimulus is relevant to performance, and that what people do is to focus on some aspect of the target, such as its configuration. The present study used eight patterns, and people focused on each pattern in eight different experimental conditions. The stimulus set was selected to have good patterns (according to symmetry, subjective goodness, and free classification measures) that were similar to each other (according to similarity judgments) and poor patterns that were dissimilar from one another and from the good patterns. The results were that the good patterns were difficult (speed and accuracy) to classify, and the poor patterns were easy. The similarity between the target pattern and the other patterns in the total set, i.e., the context of each focused stimulus, predicted performance. These results support the idea that similarity judgments measure relevant aspects of context and that the effects of context on performance should not be overlooked. © 1979 Psychonomic Society, Inc.