Schmidt and his colleagues (Machiels-Bongaerts, Schmidt & Boshuizen, 1990; Schmidt, 1982, 1983) have proposed a cognitive set-point hypothesis to explain this phenomenon.
However, the cognitive set-point hypothesis also predicts that, when total study time is unlimited both experimental and control subjects will reach the set-point for all items, and therefore show similar recall performance.
However, preliminary studies (Machiels-Bongaerts & Boshuizen, 1989) suggest that the set-point hypothesis may not only explain study time and recall patterns of items previously mobilized but also seems to apply to non-mobilized items in the same category.
In summary, according to the set-point hypothesis, mobilization of relevant knowledge prior to a processing event has two effects, both resulting in a processing advantage.
The cognitive set-point hypothesis predicts that processing information relevant to prior knowledge mobilized requires less time than processing non-mobilized information.
According to the cognitive set-point hypothesis, under this fixed study-time condition, the processing advantage acquired through mobilization would lead to superior recall of the mobilized category by the experimental groups and, hence, better overall recall.
These results confirm the predictions of the set-point hypothesis. As a result of mobilizing relevant prior knowledge the two experimental groups gained a processing advantage over the control group.
These data confirm the prediction of the cognitive set-point hypothesis that mobilizing prior knowledge facilitates the processing of both mobilized and non-mobilized items of the category activated.
The cognitive set-point hypothesis predicts that the presidents group and the States group would allot less processing time to mobilized items since these items had already been processed to a certain degree during mobilization.
The predictions of the cognitive set-point hypothesis were confirmed.
Both the study time patterns and the recall results found in Expt 2 provide support for the cognitive set-point hypothesis. The two experimental groups recalled significantly more items from the list than the control group due to the processing advantage acquired during mobilization.
However, it is important to note that, in contrast to the predictions of the cognitive set-point hypothesis, the two experimental groups did not out-perform the control group with respect to recall of items from the mobilized category.