Categorical list differentiation by mentally retarded adolescents as a function of transfer list composition and...

Likely sources of interference encountered in free-recall transfer word lists were investigated. Recall, but not recognition performance, was assumed to be sensitive to the relatively greater interference generated by old-categories transfer lists to those employing new categories. Eighty EMR subjects were assigned to the cells of a 2 (list novelty) X 2 (response mode) factorial arrangement. Since response mode was manipulated within subjects, a counterbalanced order of testing factor was also included. For the recognition task, one-half of the subjects received either same- or different-categories distractors. Results revealed that recognition performance was significantly influenced by the list novelty variation; performance was better on new- than on old-categories transfer lists. Additionally, the recognition task with same-categories distractors was associated with a greater response bias to call new items old than was the task with different-categories distractors. Results suggest that the recognition task may be more vulnerable to interference than has been previously supposed.