The Generality of the Retention Interval Model

Elaborations and refinements were made for core constructs of the retention interval (RI) model that specified a major difference between anticipation and study-test methods to be short-term memory (STM) processes in differential retention intervals. Subsequent developments reinforce the model and suggest that basic processes per each type of event are, respectively, the same for both methods (except for quantitatively differential retention intervals)-the identity hypothesis. The RI model unveiled another major factor, learning difficulty, that controls performance differences between the two methods. By encompassing new developments, the generality of the RI model was tested in a variety of situations. The model seems to hold firmly for a wide range of paired-associate and verbal discrimination learning paradigms including such cross-variations as the following: mixed vs. unmixed list design, constant vs. random item presentation orders, forward vs. backward associations, part vs. whole list designs, and visual vs. auditory modalities. Other theories, in contrast, seem to lack mechanisms to cope with inconsistent data, prevalent throughout the vast scope of learning situations.