“…The difficulty in evaluating the literature on outcomes in unequivocal terms stems in the main from its methodological deficits. One finds lack of good experimental design, failure to use the proper control groups for motivation or baseline factors (Charles, 1951;Gazda & Ohlsen, 1961;Hoyt, 1955;Ransom, 1955;Shaw, 1955;Stewart, 1958;Tresselt & Richlin, 1951;Winborn & Schmidt, 1962), or failure to use control groups ; altogether (Arbuckle, 1949;Calia, 1957;Froelich, 1958;Hewer, 1959;McGowan, 1962;Robinson, 1945;Wittenborn, 1944). There is a heavy reliance upon "beforeafter" studies and an almost predominant use of immediate rather than long-term criterion measures.…”