| Individuals with developmental disabilities often exhibit impairments in receptive and expressive language. They may not comprehend questions that use linguistic connectives such as the exclusive "or," as in "is this a dog or a cat?" As a result, they may have difficulty making choices when the choice alternatives are represented orally (i.e., "do you want___ or ___?"), versus visually (by presentation of a picture or object representing the choice alternative). The purpose of this study was to examine the effectiveness of prompting and time delay procedures in teaching individuals with developmental disabilities to make verbal choices when the alternatives were presented as a spoken question. Following assessments to determine high- and low-preference items, the students were orally offered a choice between a high- and a low-preference item. The intervention involved a prompting procedure in which the instructor provided a verbal and/or visual prompt to the student to state the verbal label of the high-preference item. Initially the prompt was delivered immediately following the offer of a choice; then the delay to prompting was gradually increased over trials, contingent upon the student's accurately choosing the high-preference item. The prompt and time-delay procedures were introduced under a multiple-baseline-across-participants experimental design. Probes were conducted throughout to assess generalization of responding to novel people. Results of the study differed for each participant. The verbal prompt + time-delay intervention was associated with an increase in accurate choice responding over baseline levels for one student. For the second student, when a visual cue was added, an increase in choice responding was noted. The intervention package was not associated with a change in responding from baseline for the third student. An increase in level of responding to novel instructors between baseline and treatment was seen for the first two participants. Due to the failure to demonstrate systematic changes in responding with the introduction of intervention with all three participants, the conclusions that can be drawn from this study are extremely limited. Results are discussed in terms of possible explanations for this failure of the same single intervention to result in changes in responding for all participants. |
