ABSTRACT
Our purposes as psychotherapy researchers are twofold. First, we seek to establish an empirical basis for the provision of psychological treatments, to find out what is helpful, for whom, under what circumstances. Second we seek to describe and understand the mechanisms of change, to find out how psychotherapies in general, and specific forms of psychotherapy in particular, achieve their effects. These two purposes are, of course, linked. Ultimately the first goal depends upon the realization of the second, which is the more intellectually challenging and exciting one.
