Comparisons of learning procedures: Effects of constant and random presentations

The retention interval hypothesis (Izawa 1972) was formulated on the basis of retention interval distributions given in random order to account for inconsistent performance differences between anticipation and study-test procedures, which have been regarded as a puzzle for nearly two decades. Under the anticipation procedure a presentation of the stimulus term of a paired-associate (a test event) is immediately followed by a presentation of both stimulus and response terms of the pair (a study event), whereas under the study-test procedure, study and test events are given on separate cycles. The retention interval hypothesis was specifically tested in a situation without any random distributions of the retention intervals i.e., under a constant item presentation order from cycle to cycle, in addition to random presentation orders, in a paired-associate learning experiment, using 80 college students. As predicted by the theory, significantly superior performances were obtained for the study-test method vis-à-vis the anticipation method also under a constant item presentation order. The constant presentation-order- arrangements significantly outperformed the random ones. Directions for further theoretical elaborations are suggested.