Zeigarnik effect the selective recall of uncompleted tasks in comparison to completed tasks. The effect was named for Bluma Zeigarnik, a student of K. Lewin, who discovered it and described it in a paper published in the Psychologische Forschung in 1927. Subjects received an array of short tasks, such as counting backward and stringing beads, for rapid completion. Performance on half of these was interrupted. Subsequent recall for the tasks favored the interrupted tasks. Zeigarnik concluded that recall is influenced by motivation and not merely associational strength. The effect was thought relevant to Freud’s claim that unfulfilled wishes are persistent. Lewin attempted to derive the effect from field theory, suggesting that an attempt to reach a goal creates a tension released only when that goal is reached; interruption of the attempt produces a tension favoring recall. Conditions affecting the Zeigarnik effect are incompletely understood, as is its significance. R.C.R.