Further investigations into post-completion error: the effects of interruption position and duration

Two experiments were carried out to examine the effect of interruption position and interruption duration on postcompletion error (PCE) occurrences in a game-like procedural task. Experiment 1 showed a significant main effect of interruption position on PCE rate; significantly more PCEs were obtained when the interruption occurred just before the PC step than interruptions at any other positions in the task. The same effect was also obtained for other non-PCEs suggesting that PCEs are no different to other non-PCEs in terms of the interruption position effect. Experiment 2 replicated the interruption position effect but did not show a reliable difference in PCE rates between a 45-sec and a 15-sec interruption. However, the trend of the differences in PCE rates between the two interruption durations is consistent with our initial prediction. The results of both experiments were explained in terms of the activation-based goal memory model (Altmann & Trafton, 2002).