A Review of Chaining Techniques: Implications for Future Research and Practice.

Although chaining procedures are a major instructional technique used in training severely handicapped learners, very little is known about which of these procedures (i.e., forward and backward chaining and total task presentation) has the most betieficial effect on learning. In this paper studies that have compared these chaining procedures are reviewed along the dimensions of independent variables, dependent variables, subject variables, apparatus variables, design, and method of analysis. In general, results of studies are mixed. Potential explanations of differences are offered. Procedures are then examined to see which of the procedures creates an optimal picture of learning and procedural variation which may effect such learning is investigated. Guidelines for future research and assistance for interpreting the present investigations are offered. Use of various chaining techniques is frequently as a conditioned (secondary) reinforcer for the cited in the behavioral and special education previous response. literatures as a major instructional method in In the applied setting the series of discreet the training of severely/profoundly retarded behaviors that precede the terminal response learners (e.g., Azrin & Foxx, 1971; Azrin, are analyzed into links, steps, or teachable com Schaeffer, & Wesolowski, 1976; Gold, 1972, ponents. Gaylord-Ross (1982) and Sailor and 1976; Hunter & Bellamy, 1976; Watson & UzGuess (1983) call this component analysis "task zell, 1981). Chaining techniques have also reanalysis" and suggest that chaining procedures ceived substantial attention in introductory as are the most commonly used methods of task well as methods textbooks in the field of special analysis. The application of chaining is then the education (Greer, Anderson, & Olde, 1982; sequence or order in which the components are Repp, 1983; Sailor & Guess, 1983;Snell, 1983). taught. There are three widely used types of A chain is a specified series of responses, each chaining in applied settings: Backward chaining, associated with a unique stimulus condition, with forward chaining, and a variation of forward the delivery of a reinforcer at the completion chaining, total task presentation, of the last link. Kelleher (1966) as well as BelAlthough all three chaining procedures com lamy, Inman, and Schwarz (1978) suggest that prise a salient portion of the instructional in a chain each relevant stimulus condition method/strategies used by trainers of severely should function in two ways: first, each link handicapped learners, there is a paucity of re should act as a discriminative stimulus, i.e., set search on comparisons of these procedures, the occasion for the subsequent response in the Sulzer-Azaroff and Mayer (1977) as well as chain, and second, each stimulus should function Sternberg and Adams (1982) indicate that there is insufficient evidence to draw clear conclusions 1 The authors would like to acknowledge the supabout comparisons of chaining procedures be port of Mary K. Dykes, and Henry S. Pennypacker, cause not much research has been conducted University of Florida; Harold W. Heller and Terry with human subjects. L. Rose, University of North Carolina at Charlotte; r , . t ir i t j* i_ t* t" ii i ^ . The purpose of this paper is to examine and James E. and Judith E. Favell and Carol Tnvette, i • » • f r » • • Western Carolina Center, Morganton, North Carsynthesize research in the area of chaining pro olina, during the development of this manuscript. cedures used to train severely mentally retarded Meda Smith, Western Carolina Center, is thanked persons. A key area of concentration is the de for typing the final manuscript as well as previous gree to which the dependent variables of choice drafts. and the measurement system evoked on those 114 / Education and Training of the Mentally Retarded-April 1984 This content downloaded from 207.46. 13.145 on Wed, 27 Apr 2016 06:56:13 UTC All use subject to http://about.jstor. org/terms dependent variables interact with the indepengether. When using the total task procedure dent variable(s) to produce optimal learning. (TT), the learner begins with the first step of Because there is a lack of documentation in the the task, but every step in the sequence is trained literature on comparisons of these procedures every trial until the subject performs the whole with severely handicapped learners, researchers task to a predetermined criterion (Gold, 1976). who have conducted comparison studies with The least procedural variation is with TT, train higher functioning individuals (i.e., mild/modevery step every trial, until learner is performing erate) have been included in this review. every step as a unit without assistance. It is clear from a review of the procedural definitions in Table 1, that the independent variables under Comparisons of Backward Chaining, Forward investigation are succinctly stated and all inves Chaining, and Total Task Presentation tigators are observing the effects of similar op erational definitions of independent variables on Table 1 is a representative sample of the comsubject responding. parison studies that have been conducted in the Dependent Variables. A careful review of Ta area of chaining. Comparison of these proceble , suggests that the major dependent variab|es dures is the appropriate, timely, level of invesof imerest are; (a) time t(J criterion; (b) number ligation because previous work (Arzin et al., of incorrect reSponses; (c) number of correct 1976; Bellamy, Peterson, & Close, 1975; Gold, resp0nses; (d) rate of correct responses; and (e) 1976; Hunter & Bellamy, 1976; Watson & Uzrate of incorrect responses. Another likely de zell, 1981) has identified the effectiveness of pendem variab,e is tHals tQ criterion. From a chaining procedures in isolation. It is through measurement perspective, defined as "the pro comparative investigation and analysis that difcess of assigning numbers and units to objects ferential procedural effects and nuances of deor evems„ (johnston & Pennypacker, 1980, pendent variables (i.e., response rate) will bep 119)> a„ of the dependent variables under come apparent. The outcomes of these invesinvestigation adhere to the number criterion of ligations set the occasion to look for the measurement (e.g., number of correct responses, procedural features which produce optimal trja,s tQ criterion). but few of tbe dependent learning. variables found in Table 1 meet the second cri terion of measurement, standard units which accompany the number (i.e., number of correct responses per minute). Independent Variables. Procedural definitions do Subject Variables. Subjects from study to study not appear to differ substantially. In backward appear to differ substantially. For example, chaining (BC), usually, one step of the task is Walls, Zane, and Ellis (1981) used mild/mod trained at a time, in a reverse sequence, starting erate retarded persons (I.Q. range not specified) with the last step. Next, the second to the last while Volgelsberg (1978) and Spooner (1981) step becomes the "training step" and the learner used severely/profoundly retarded populations, performs the step that he/she has already Sailor and Guess (1983) comment that use of learned (the last step). The sequence continues, the TT procedure tends to be favored by persons adding a new training step and the learner perworking with cognitively higher functioning forms the other steps that have previously been students, particularly teaching personnel asso learned until the learner is performing all steps ciated with secondary severely handicapped independently. In forward chaining (FC), one programs. On the other hand, when comparisons step of the task is trained at a time, in a forward were made with cognitively higher functioning sequence, starting with the first step. The first populations (i.e., mild/moderate, Nettlebeck & step is learned to a predetermined criterion, with Kirby, 1976; Walls et al., 1981), the TT pro subsequent steps being added one at a time, until cedure did not produce superior results, the trainee performs the whole task. In FC, there Apparatus Variables. Although the skills nec are some procedural differences. For example, essary to assemble a coaster bicycle brake may Patterson, Panyon, Wyatt, and Morales (1974), be a different set of skills than those necessary trained independent steps in forward sequence to perform a dressing task, the tasks used from to a separate criteria before linking them tothese studies could generally be grouped under Chaining / 115 Synthesis of Variables This content downloaded from 207.46. 13.145 on Wed, 27 Apr 2016 06:56:13 UTC All use subject to http://about.jstor. org/terms