Information-processing correlates of computer-assisted word learning by moderately and severely mentally retarded students were identified. Nineteen subjects completed 10, 15-minute computer-assisted instruction sessions and seven basic cognitive tasks measuring simple learning, choice reaction time, relearning, probed recall, stimulus discrimination, tachistoscopic threshold, and recognition memory. Stimulus discrimination, probed recall, and simple learning were significantly related to word learning. Results suggest that instruction should be modified to accommodate individual differences in these abilities.