Evaluating treatment effectiveness in cerebral palsy. Single-subject designs.

Methods to empirically evaluate treatment effectiveness for individual patients or small groups of patients are presented. Different types of single-subject (as opposed to group) experimental designs are described, and their appropriateness for heterogeneous populations such as the cerebral palsied is discussed. Possible errors in attributing causality are noted and illustrated. Techniques or behavioral analysis and various types of single-subject designs are presented, including the AB, ABA, ABAB, and multiple baseline across subjects, behaviors, and settings. The procedures are shown to produce reliable data from which conclusions about the relationship between treatment and behavior change can be made. The generalizability of single subject methods to different patients and problems is also discussed.