David L. Gast

Effective and Efficient Procedures for the Transfer of Stimulus Control

This paper describes and reviews procedures for transferring stimulus control. Assumptions for using these procedures are included. Four response prompting and two stimulus manipulation procedures are discussed. The response prompting procedures are most-to-least prompts, graduated guidance, system of least prompts, and time delay. The stimulus manipulation procedures are stimulus shaping and stimulus fading. Recommendations concerning the use of these procedures by teachers are made, and questions for further research are noted.

System of Least Prompts: A Literature Review of Procedural Parameters

This manuscript describes an instructional strategy, system of least prompts, and reviews the use of the procedure in the applied research literature. The literature is analyzed in terms of the populations for which the procedure has been used, the type of skills that have been taught with the procedure, and the results when the procedure was employed. The literature also is described in terms of previously identified parameters of the system of least prompts including (a) the number and type of prompts included in the least-to-most assistance prompt hierarchies, (b) the presentation of the target stimulus at each prompt level, (c) use of a fixed response interval, and (d) the delivery of reinforcement following correct prompted and unprompted responses. Summary statements and recommendations about future use and research are included.

Stereotypic behavior as a reinforcer: Effects and side effects

This study assessed the effects and side effects of using stereotypic behavior as a consequence for correct responding with two autistic children. The children were cued through a model to engage in stereotypic behavior contingent upon correct responses in tasktraining sessions. This instructional arrangement produced increases in the percent of correct responses. Measures of the stereotypic behavior used as a reinforcer, other stereotypic behaviors, and appropriate behaviors were collected during daily 5-minute free operant settings before and after the tasktraining sessions. No replicable, systematic changes in the percent of intervals in which subjects engaged in those side effect measures were noted. Thus, a new method for delivering stereotypic behavior as a reinforcer was investigated and produced reinforcing effects; the rate of that behavior in free operant settings was not adversely affected.

Applying Time Delay Procedure to the Instruction of the Severely Handicapped

Research is reviewed that employs delay procedures with the severely handicapped as a means of shifting stimulus control. The parameters of delay procedures are delineated, including prerequisite student and teacher considerations, types of responses, levels of delay, single versus blocked trials, and basic delay methodology. Four special situations are discussed: tasks involving a choice, tasks necessitating an intermix procedure, students with long response latencies, and warm-up trials. Remediation strategies are suggested for handling students who make excessive errors or who fail to anticipate. Finally, techniques are described to encourage maintenance and generalization of learned skills.

Use of a Constant Time Delay Procedure in Teaching Preschoolers in a Group Format.

The primary purpose of this Investigation was to evaluate the effects of constant time delay (a near-errorless teaching strategy) in teaching preschoolers sight word reading in a group. A secondary purpose was to assess the effects of two attentional responses, specific (repeating the letter names) and general (looking at the stimulus cards) on observational and related, nontarget learning. A multiple probe design across pairs of words was used to evaluate the procedure. The results of the investigation indicate that (a) constant time delay was reliably implemented in a group setting, (b) constant time delay was effective in teaching all targeted stimuli in near-errorless fashion, (c) observational and related, nontarget learning (expressive labeling of words, receptive identification of words, matching words to pictures and pictures to words, and receptive spelling of words) occurred across students, and (d) the specific attending response resulted in greater expressive labeling, receptive identification, and receptive spelling of other childrens target words than did the general attending response.

Comparison of Response Prompting Procedures in Teaching Numeral Identification to Autistic Subjects.

This investigation compared the effectiveness and efficiency (sessions, trials, percentage of errors, direct instructional time through criterion, and incidental information learned) of constant time delay and system of least prompts in teaching students with autism to name numerals. Two sessions were provided each day; one with constant time delay and one with system of least prompts. Two students learned 16 numerals, and one student did not learn any numerals with these two procedures. The parallel treatments design was used to assess the effects of the two instructional strategies. The results indicate that both procedures were effective in raising responding to criterion levels for two subjects. The constant time-delay procedure was more efficient than the system of least prompts procedure in terms of sessions, trials, percentage of errors, and direct instructional time through criterion.

A comparison of time delay and system of least prompts in teaching object identification

This study is a comparison of two response prompting procedures: Progressive time delay and system of least prompts. Three students with severe handicaps were each taught to identify eight functional objects, four objects with each prompting procedure. The procedures were compared in terms of effectiveness (establishing criterion level correct responding) and efficiency, (sessions and trials to criterion, errors to criterion, and the number of minutes of direct instructional time). A combination of two concurrently operating multiple probe designs (Parallel Treatments Design) in which extraneous variables were counterbalanced across sessions was employed. An analysis of the results indicates that both prompting procedures were effective in establishing correct responding at criterion levels, but the time delay procedure required fewer sessions, trials, and errors to criterion, and fewer minutes of direct instruction time than did the system of least prompts. Issues for further comparative research are discussed.

Legal and Ethical Considerations for the Use of Timeout in Special Education Settings

Timeout from positive reinforcement has become one of the most frequently used strategies by teachers for suppressing disruptive behavior. Accompanying this increase in popularity has been increased public scrutiny and concern for the uses and abuses of timeout interventions. This article examines the parameters of timeout which need to be considered by teachers before implementing such procedures in the classroom. Also included is a review of recent court decisions addressed to timeout interventions. Specific recommendations, based on this legal and research literature, are presented.

Teaching a Multihandicapped Adult Manual Signs Using a Constant Time Delay Procedure

A 31-year-old severely hearing impaired young man, with mild to moderate retardation and cerebral palsy, was taught to sign labels manually for six photographs of people, places, and objects found in his work environment. A constant 4-second time delay procedure was used as well as a multiple probe design across manual signs. Generalization probes were conducted: (1) to measure the extent to which the worker could successfully comprehend these same signs after expressive sign training, although no direct receptive sign training was provided and (2) to test whether he could identify actual people, places, and objects in his work environment. The worker learned to produce all six manual signs in near-errorless fashion. In addition, after reaching criterion on sign production, he was able (1) to label actual people, places, and objects found in his work environment and (2) to comprehend these same signs. The constant time delay transfer of stimulus control procedure proved to be both an effective and efficient instructional method.

Establishing conditional discriminations: Concurrent versus isolation-intermix instruction

This paper describes an investigation comparing the effectiveness and efficiency (sessions to criterion, errors to criterion, minutes of instructional time) of concurrent and isolation-intermix instruction in teaching four preschool children to read words found in community and school environments. Two students were taught words using constant time delay and two progressive time delay across the two different conditions. Concurrent instruction consisted of two sessions per day where two words were randomly presented within each session until criterion was reached and a conditional discrimination was established. The isolation-intermix condition involved two sessions per day where each word was taught in separate daily sessions until criterion was reached and a simple discrimination was established (isolation instruction); followed by random presentation of both words within each daily session until the conditional discrimination was acquired (intermix). Concurrent instruction resulted in students learning conditional discriminations in fewer trials and minutes of instructional time. These data suggest that teachers should structure their instruction to teach conditional discriminations from the beginning rather than teaching simple discriminations.