Memory units and the composition of recall

The unitization hypothesis of organization predicts that different levels of free recall should be accounted for by the number of additional items recalled as part of higher order memory units. This prediction was tested by using various instructional procedures to obtain different levels of total recall from normal elderly subjects, identifying their memory units in order to analyze the composition of recall. The composition of recall shows that different levels of recall are accounted for by the number of additional items recalled as part of a constant number of multiitem units. These results directly confirm the unitization hypothesis.