One of the early and proud boasts of the founders of personcentred therapy is that its theory was ®rmly rooted in the empirical observation of practice and that this was unique. Also, Rogers and his early students saw themselves as scientists who sought to establish a basis for their beliefs and practices by actively engaging in research. Rogers was not alone in this early, innovative research work. For example, Barrett-Lennard (1998: 11±12) recorded that in the 1940s each graduate student working with Rogers at Ohio State University typically contributed `a discovery in method, technique or theoretical formulation in the previously uncharted ®eld of empirical research on psychotherapy'. Rogers moved to the University of Chicago in 1945 and from there to the University of Wisconsin where he was from 1957 to 1963. McLeod (2002: 88) writes that:
During the whole of this 25-year period Rogers was the leader of a systematic programme of research into the processes and outcomes of client-centered therapy. The client-centered research group comprised the largest centre for research in psychotherapy then in existence.