The more, the better? Number of decisions as a determinant of memorability

Three experiments tested alternative explanations to the Johnson-Laird, Gibbs, and deMowbray (1978) proposal that the number of decisions made about a word is a major determinant of its memorability. The alternatives considered were increased processing time, retrieval aids, and the number of positive decisions. In Experiment 1, subjects made a speeded classification about each word for a category defined by three properties. Though items with more target properties were processed longer and better remembered, within a property level processing time was not associated with better memory. In Experiment 2, subjects received three properties, but different groups responded "Yes" to words with all three properties, words with any of the three properties, or whether words had each of the properties. As predicted by the number-of-decisions hypothesis, but not by the other hypotheses, with an increasing number of target properties, recall generally increased in the ALL group, decreased in the ANY group, and remained constant in the EACH group. In Experiment 3, this recall pattern was replicated with a different set of two target properties. The number-of-decisions notion is contrasted to the elaboration principle, and a simple model is proposed. It is concluded that the number of decisions is a useful technique for investigating within-level encoding differences