Teaching is a primary responsibility of the field work supervisor, and field work is a course in the curriculum just as casework or social administration are courses—but with some differences to be elaborated later. American social work literature tells the reader that earlier education for social work practice really represented vocational training for specific agency tasks under specific agency auspices. Social work literature on the subject of supervision has much to say about the three-fold function of the present-day supervisor administrative, helping and teaching. There has been much thinking by American social work educators in recent years about curriculum planning, and about the whole gamut of social work education as an educational experience. The cognitive theorists believe that thinking is related to central brain processes which involve memories and expectations, and that thinking processes involve goal-seeking behavior. Nowadays most educators seem to prefer the cognitive theories to the stimulus-response theories to describe learning activity.