“…Success in terms of positive student reaction, lower dropout rates and higher final examination scores has been widely reported (Anderson and Pritchett, 1977; Peluso and Baranchik, 1977;Rogers and Young, 1977;Struik and Flexer, 1977;Waits and Riner, 1975;Weir, 1977). Thompson (1980) stands nearly alone in reporting no difference between PSI and traditional treatments in a very large well-organized study conducted in connection with a calculus course at the United States Air Force Academy.…”