“…However, theory and experimental re search support the efficacy of individual model com ponents. Successful skill acquisition by learners with moderate to severe disabilities has been shown in studies that have distributed training trials within an instructional session (e.g., Dunlap, 1984;Kayser, Billingsley, & Neel, 1986;Mulligan, Lacy, & Guess, 1982) and across several different classroom activities or school routines (e.g., Campbell & Stremel-Campbell, 1982;Hunt, Goetz, Alwell, & Sailor, 1986). Further more, trial distribution alone (i.e., without functional trial sequencing and in-context instruction), has been shown to have advantages over the traditional massed trial training format.…”