The interruption of tasks: Methodological, factual, and theoretical issues.

After describing the criterion scores which have been used to assess behavior in the interrupted task paradigm (ITP), a summary of the research literature is presented. ITP as a source of data for evaluating the psychoanalytic theory of repression is found not to allow for the separation of learning and retention effects, and so is not well suited to the study of repression. Similarly, the mediation-avoidance hypothesis makes predictions only concerning interrupted task recall and while it is partially consistent with indirect data, it has yet to receive direct experimental test. The need-achievement conception predicts interrupted task recall satisfactorily but is inapplicable to completed task recall or relative recall scores. Finally ITP is considered as a source of data for a developmental conception of success-failure reactions, Repetition choice scores are found to be consistent with the developmental theory, but some recall results are not. In the interrupted task paradigm (ITP) the subject (5) is engaged in a number of tasks some of which he is allowed to complete and some of which are interrupted before he completes them. Zeigarnik (1927) first introduced ITP as a test of the prediction from the gestalt theory of motivation that interrupted tasks should be recalled more frequently than completed tasks. Her findings supported this prediction and is known to this day as the Zeigarnik effect. However, ITP encompasses more than just the Zeigarnik effect or even the recall of tasks. In the first place, the Zeigarnik effect is far from being the invariable result in ITP. Frequently, more completed than incompleted tasks are recalled (e.g., Atkinson, 1953). In the second place, measuring the relative recall of com-