ONE OF THE most encouraging advances in the field of behavior therapy in recent years has been the growth of in formed interest in the subject. Numbers of psychologists and psychiatrists are now aware of the main tenets and major aims of this type of treatment. This growth of interest has of course been accompanied by a burgeoning of research work on the subject. This is evidenced by the increasing inclination to subject the techniques of behavior therapy to experimental investigation. In particular, there have been a number of studies in the past few years which have been designed to estimate the effects of behavior therapy. In addition, there have been some new developments of the original techniques and the introduction of entirely new methods. Research into the effects of behavior therapy can be divided into two main categories: those studies which have employed control groups and those which have