ABSTRACT
The unaided recovery of previously unrecallable items was demonstrated by Tulving (1967) in an experiment in which he gave subjects a single presentation of a word list and required three successive recall attempts. Although about half of the list words were recalled on each trial they were not all the same words. Thus, some words which were not recalled on one trial were recalled later, while others recalled on an early trial were not recalled in a subsequent one. The early failure to recall items which were later recalled cannot, of course, be attributed to storage loss because it would not then be possible to recover them at all. These items, therefore must have been available in memory but not accessible. An important aspect of Tulving’s results is that although the actual words changed, the number of words recalled on each trial was nearly constant. This implies that, in some circumstances at least, there is a limit on the capacity of the retrieval process, i.e. only a certain number of items can be accessed on a particular trial.
