Divided Ss into three groups on an interruption-of-tasks experiment on the basis of instructions presumed to vary the probability that the Ss would perceive completion as personal accomplishment and incompletion as personal failure. Each S was also classified high or low in motivation to achieve based on a thematic apperception measure of the need to achieve. Found that recall of incompletions and the tendency to show the Zeigarnik effect increased for Ss high in achievement need as instructions increased the probability that completion and incompletion would be perceived as success and failure while just the opposite trend occurred for Ss low in achievement need. An attempt is made to reconcile the contradictory results relating to the Zeigarnik effect. 22 references. (PsycINFO Database Record (c) 2006 APA, all rights reserved)