Number of stimulus items presented together (one, three or five) and instructions to organize were studied in a multitrial free recall experiment with 83 educable retarded adolescents. Results of individual sessions in which Ss were asked to recall 15 common words indicated that presentation of three stimuli together produced the highest subjective organization but that this blocking did not influence overall number of correct responses. Blocking did, however, extend the recency effect in the serial position curve. Instructions to organize resulted in neither higher organization nor more correct responses. (Author/CL)