“…Appreciation is expressed to Robert E. Crow, Terry Page, Kenneth E. Bauman, and John D. Cone for their assistance in writing the manuscript, to Barb Lowther for assistance in data collection, to Cheryl Trgovich for assistance in preparing the manuscript, and to Mary Ann Powers for her project suggestions. Reprints may be obtained from Dennis H. Reid (Bricker, Morgan, and Grabowski, 1972;Hollander and Plutchik, 1972;Hollander, Plutchik, and Horner, 1973) as reinforcing stimuli. Group contingencies (Reid, Schuh-Wear, and Brannon, 1978) and behavioral lotteries (Iwata, Bailey, Brown, Foshee, and Alpern, 1976) have also received attention.…”