Therapists and educators frequently teach alternative-communication systems, such as picture exchanges or manual signs, to individuals with developmental disabilities who present with expressive language deficits. Michael (1985) recommended a taxonomy for alternative communication systems that differentiated between selection-based systems in…

The objective of this study was to teach manual signs through an automated matching-to-sample procedure and to test for the emergence of new conditional relations and imitative behaviors. Seven adults with mild to severe mental retardation participated. Four were also hearing impaired. Relations between manual signs (set A) and pictures (set B)…

Although the verbal operants that comprise Skinner's account of verbal behavior provide a seemingly complete description of the behavior of the speaker with respect to what is ordinarily called the expression of meanings, it may be shown that the account is intrinsically deficient in describing the receptive behavior of listeners with regard to…