Does a Production Deficiency Hypothesis Account for Vocabulary Learning Among Adolescents with Learning Disabilities?

To test a production deficiency view of learning disabilities, students identified as learning disabled or normally achieving were compared on a vocabulary learning task. Subjects studied a list of words and definitions and then took a sentence completion vocabulary test. Subjects were not told how to study. The learning disabled group learned fewer words than the normally achieving group, as indicated by vocabulary learning test scores. The two groups did not differ in the observable learning strategies used during the study period; the most frequently observed strategy was rehearsal with self-testing. For all subjects, strategy use did not account for vocabulary learning score. Scores on standardized reading vocabulary and comprehension tests predicted vocabulary learning test score for the total group. The implications of these findings relative to a production deficiency view of learning disabilities are discussed.