The monograph defines and discusses single subject research designs in special education. Advantages of this approach with measuring change in handicapped children are noted. Observational techniques (event recording, duration recording, interval recording, and time sampling) are described, along with three types of single subject evaluation procedures (A-B, reversal, and multiple baseline). A final section considers the presentation and interpretation of results. The authors conclude that the methodology of the single subject approach is simple and well suited to the individualized education program requirement of P.L. 94-142, the Education for All Handicapped Children Act. (CL)