The program entitled Prevention of Learning Disabilities: An Interdisciplinary Model, developed and operated by the Learning Disorders Unit of New York University Medical Center, has three elements: scanning, diagnosis, and intervention. Educational intervention is done primarily by Board of Education teachers and educational assistants under the supervision of the Learning Disorders Unit staff. Children are taught individually or in small groups three to five times each week in sessions lasting 30 minutes. The prescriptive approach employed, designed to build foundation skills necessary for progress in reading, provides directed activities to teach accuracy of perception within single modalities and intermodal skills to relate input of several modalities. Educational plans are implemented with tasks proceeding through three stages of increasing complexity: matching, copying, and recall. Evaluation of the model has indicated that, in contrast with controls, program participants improved in perceptual skills and oral reading, word recognition, phonics skills, and reading comprehension. The effectiveness of intervention has been demonstrated in a nonpromotion rate for participants of 5 percent or less. Followup data has enabled examination of additional issues, including (1) implications of early cognitive intervention on pupil adjustment, (2) sex differences in vulnerability to learning disability, and (3) the role of subgroups existing within the sample of vulnerable children. Longitudinal aspects of the evaluation have shown that educational achievement differs among subgroups. (RH)