Effects of multiple exemplar instruction on transformation of stimulus function across written and vocal spelling responses by students with autism.

Introduction According to Skinner (1957), speaking and writing are different kinds of verbal operants that initially must be "separately conditioned" (p. 191). Skinner (1957) proposed that words that occur in written form are functionally independent of the vocal form of the same word. He refers to this as the "same response in different media" (p.191). On this topic, Skinner wrote: But speaking and writing are obviously different kinds of behavior, which utilize different parts of the body in different ways. Where we could paraphrase "the same word used in different ways" as "the same response in different types of operant," here we must attempt to bridge the gap between spoken and written behavior either by pointing to something common to the occasions upon which the behaviors occur or among the effects which they have upon the listener and reader. But common controlling variables, action either prior to the behavior in the stimulation occasion or after the behavior as part of the event called reinforcement, will not permit us to get from one form of the response to the other. The two forms of behavior must be separately conditioned. (p. 191) Consistent with Skinner's theory, several types of verbal operants are initially independent including: mands and tacts (e.g., Lamarre & Holland, 1985; Hall & Sundberg, 1987; Twyman, 1996; Williams & Greer, 1993), listener and speaker responses (Horne & Lowe, 1996), and written and spoken responses (Greer, Yuan, & Gautreaux, 2005). Recent research reported the effectiveness of multiple exemplar instructional methods in joining separate verbal operants to a single controlling stimulus, such as with listener and speaker responses (Horne & Lowe, 1996; Fiorile & Greer, 2007; Greer, Stolfi, Chavez-Brown, & Rivera-Valdez, 2005; Pistoljevic, 2008), and with written and spoken responses (Greer, Yuan, et al., 2005). Similarly, Nirgudkar (2005) and Nuzzolo-Gomez & Greer (2005) joined single responses to the control of different establishing operations for mand and tact operants as a function of multiple exemplar instruction (MEI) across establishing operations. According to Greer & Ross (2008) MEI) (also known as multiple exemplar training or MET) has been described in the literature in two ways. In one use of the term (also called general case teaching), MEI refers to a tactic in which different examples of the same stimulus are presented when teaching generalization or abstraction (e.g., Hughes & Rusch, 1989; Sprague & Horner, 1984). For example, teaching textual responses to phonemes across multiple exemplars results in the emission of accurate textual responses to novel words (Engelmann & Carnine, 1982). In another usage, MEI refers to a tactic used to bring independent operants (e.g., writing, spelling aloud, and textually responding) under joint stimulus control for novel stimuli by rotating different responses to a single stimulus in instructional sets (Greer, Yuan, et al., 2005; Fiorile & Greer, 2007; Greer, Stolfi, et al., 2005). That is, "the manipulation of initially independent response topographies with the same stimulus may generate the joint stimulus control such that a single stimulus can evoke both responses" (Greer, Yuan, et al. p. 100). In the study described herein, the latter description of MEI applies. Greer, Yuan, et al. (2005) tested the effect of MEI across written and spoken responses in instructional sets on the acquisition of untaught spelling responses in the vocal or written form, for four young children, using a delayed multiple probe design. After an initial test showed that the participants could not spell three sets of five words, the participants were taught to spell Set 1 words in one response form (either vocal or written), and after achieving mastery in the taught form, probes were conducted on the untaught form. …