One of the areas receiving the greatest attention from researchers studying autism spectrum disorders in recent years involves psychologically based early intervention programs. Various claims of cure, marked improvement in social and communication skills, and improved I.Q. are among the conclusions that have been drawn by various researchers. However, little has been done to analyze the dependent variables used in these studies and their impact on the conclusions reached regarding treatment effectiveness. Obviously, this set of measures is crucial since these methods define which behaviors "improved" and to what extent. The present review analyzes the current status, strengths, and weaknesses of these measurements.