“…Many studies have measured the effect of amount of prior training on the degree of control that a stimulus acquires for discrimination or generalization tasks (Farthing & Hearst, 1968;Hearst & Koresko, 1968;Rilling & Budnik, 1975;Sewell & Nickel, 1979;Thomas & Williams, 1963) and reversal (Lovejoy, 1966;Mackintosh, 1965Mackintosh, , 1969McAllister, Capehart & Rogers, 1970;Reid, 1953). In general, results from this body of research show that additional training (or "overtraining", as it is sometimes called) improves stimulus control and leads to faster reversal, although this effect is far from simple and, again, there are conflicting results.…”