“…In general, such outcomes are more likely when stimulus classes that are established by training relate to existing receptive and expressive repertoires. Indeed, Sidman's findings have been replicated across a variety of procedures with participants who possess such entry skills despite considerable variation in developmental status and hearing acuity (e.g., Hollis, Fulton, & Larson, 1986;Joyce & Wolking, 1989;Mackay, 1985;Mackay & Sidman, 1984;Osborne & Gatch, 1989;Stromer, 1996a). Sidman's (1971) and Sidman and Cresson's (1973) name-referent (e.g., picture, word, and symbol) matching procedures have also been used with young children without developmental disorders (Sidman, Kirk, & Willson-Morris, 1985;Sidman & Tailby, 1982;Sidman et al, 1986) and persons with mental retardation (Green, 1990;Sidman et al, 1986).…”