Three levels of screening procedures were used to identify the incidence and nature of learning disabilities. The first level involved the application by classroom teachers of the Classroom Screening Instrument (CSI), especially developed for the study, and of other measures; the second level involved psychoeducational differential diagnosis by qualified testers; and the third, medical examinations by appropriate personnel. Screening of 2,400 second grade children at level 1 resulted in identification of 361 for level 2 screening, of whom 134 were selected for level 3 screening. Results indicated that classroom teachers could use the CSI with accuracy to identify children with varied learning problems. The study further indicated approximate incidences of 4.7% for severe learning disabilities and 6% for less severe learning disabilities. A technical report is given in volume 1; descriptive data and statistical analysis are provided in volumes 2 and 3, respectively. (JD)