Serial Order Intrusions in Immediate Memory

The theory that serial order intrusions in immediate memory lead to recall errors was tested experimentally. It was found that increasing the time interval between successive 8‐digit messages had no effect on recall performance. Analysis of the response errors showed that with a short interval between messages, serial order intrusions occurred, but they did not occur with long intervals. Thus the amount of error appeared to be independent of the number of intrusions. It is suggested that intrusions occur after recall has failed—there being no causal relationship.