While there is strong empirical evidence in the literature that, without interpolation, massed or distributed presentation of categorizable word pairs affects both storage and retrieval processes, theories of retroactive inhibition tacitly assume that presentation mode does not play a substantial role with interpolation. By means of Batchelder and Riefer's (1980) storage-retrieval model this supposition is examined for its empirical soundness. First to be discussed is whether with interpolation the presentation mode influences storage and retrieval in memory. The question of whether a distributed mode can induce storage loss is emphasized here. Second, it is to be discussed whether Batchelder and Riefer's (1980) two-factor hypothesis can be generalized to retroactive inhibition. This hypothesis postulates a smaller probability for storage and a larger probability for retrieval when categorizable word pairs are presented in a distributed manner.
A free recall experiment is reported with two experimental factors: interpolation level (1–5 lists presented) and presentation mode (massed versus distributed). For the massed mode the data analysis shows a retrieval failure without storage loss, while for the distributed mode some storage loss occurred. These data reveal that presentation mode does indeed affect storage processes in retroactive inhibition. Furthermore, when interpolated lists are presented, distributed presentation reduces storage probability, while retrieval probability remains unaffected. Batchelder and Riefer's two-factor hypothesis, therefore, cannot be generalized to retroactive inhibition.