Process, not representation: Reply to Radvansky (1999)

The size of fan effects is determined by processes at retrieval, not by whe ther or not information is represented as situations. Evidence contradicts G. A. Radvansky's (1999) claim that time to retrieve information from a sit uation does not depend on the number of elements in the situation. Moreover , Radvansky's principles for ascribing situational models to experiments ap pear to be post hoc ways of redescribing the data. On the other hand, the e vidence does support the Adaptive Control of Thought-Rational (ACT-R) assum ption that participants can adjust their attentional weightings and so prod uce differential fan effects. Moreover, the ACT-R theory of the fan effect is consistent with many other findings.