“…Also, instructional variables such as choral and individual responding in small-group arrangements have been compared (Kamps, Dugan, Leonard, & Daoust, 1994;Wolery, Ault, Doyle, Gast, & Griffen, 1992) and different methods of presenting instructive feedback have been evaluated (Werts, Wolery, Holcombe, & Gast, 1995). Several measures of instructional efficiency are possible, such as the number of behaviors learned (Holcombe, Wolery, Werts, & Hrenkevich, 1993); number of sessions, minutes, and trials to criterion (Ault, Gast, & Wolery, 1988); and number and percentage of errors to criterion (Godby, Gast, & Wolery, 1987). Another defensible measure is permanent transfer, which is defined as the session in which all subsequent sessions result in a majority of the responses being correct unprompted responses.…”