ABA is grounded in the use of frequent positive reinforcement and research has shown when behavior is rewarded or reinforced, the individual is more likely to repeat it. ABA is an evidence-based method to improve functioning in individuals. When ABA has been determined to be the treatment protocol, it must be decided what principle to use; one such approach is chaining. A behavior chain is a classification of related behaviors, in which each step provides the prompt for the subsequent step, and the last step produces a reinforcer. Chaining procedures can be employed with children and adults. Chaining can be further subdivided into forward, total-task, or backward chaining. Chaining procedures have been used with individuals with diagnoses including, schizophrenia, intellectual disabilities, autism spectrum disorders, attention deficit hyperactivity disorder, developmental disabilities, and pediatric feeding disorders.
Keywords: Applied Behavior Analysis, Forward Chaining, Backward Chaining
Applied Behavior Analysis: Chaining
One of the most researched, reviewed, and implemented evidenced based therapies to date is applied behavior analysis (ABA). ABA is an intervention based on learning theory principles aimed at improving the functional, communication, and social skills of individuals (Cooper, Heron, & Heward, 2007; Maglione, Kadiyala, Kress, Hastings, & O’Hanlon, 2017; Walsh ; College, 2009). In their pioneer description of ABA as a discipline, Baer, Wolf, and Risley (1968) asserted ABA is technological, meaning its intervention techniques or procedures are clear-cut, comprehensive, and able to be duplicated.
ABA requires the implementation of “established principles of learning, behavioral strategies, and modifications to the environment to improve and teach replacement behaviors” (Hendricks, Palko, ; Dreyfus, 2015, para. 2). When using ABA methods, procedures must be systematic so professionals can identify how behavior can be changed and understand how learning occurred (Cooper, Heron, ; Heward, 2007). The aim of ABA is to establish and maintain socially significant behaviors; such behaviors can include academic, social, communication, and daily living skills (Cooper, Heron, ; Heward, 2007). Hendricks, Palko, and Dreyfus (2015) reported ABA can be used to target “any skill to enhance the independence or quality of life for the individual” (para. 1). ABA uses intervention methods and procedures to identify antecedents and consequences that will result in the increase of positive skills and the decrease behaviors. Decisions regarding the effectiveness of the intervention are based on data collected; data must drive instructional decisions (Cooper, Heron, ; Heward, 2007).
Baer, Wolf, and Risley pioneered the seven dimensions of ABA (1968); they described the fundamental characteristics of behavior analysis which meticulously illustrated the application of behavior from experimental to the conceptual analysis of behavior. The seven identified features critical to ABA are that treatments be applied, behavioral, analytic, technological, conceptual systems, effective, and general (Baer, Wolf, and Risley, 1968). Baer, Wolf, and Risley (1968) asserted treatments that do not feature all seven dimensions are incomplete and potentially compromised in effectiveness.
ABA Research Review
ABA is grounded in the use of frequent positive reinforcement; when behavior is rewarded or reinforced, the individual is likely to repeat it. With over 40 years of research to support it, ABA is an evidence-based method to improve functioning (Cohen et al., 2006; Cooper, Heron, ; Heward, 2007; Eikeseth et al., 2002, 2007; Howard et al., 2005; Maglione, et al., 2017; Sallows ; Graupner, 2005; Virués-Ortega, 2010). A review of the research indicated students receiving ABA make significantly more gains on standardized measures of IQ, language and adaptive functioning (Cohen et al., 2006; Eikeseth et al., 2002, 2007; Howard et al., 2005; Maglione, et al., 2017; Sallows ; Graupner, 2005; Virués-Ortega, 2010). Since its original inception as a non-medical treatment in the 1930s, ABA has proven successful in helping individuals develop cognitive, language, and communication skills (Cooper, Heron, ; Heward, 2007).
The effects of ABA treatment were evaluated by Smith, Groen, and Wynn (2000). Their findings indicated the ABA treatment group scored significantly higher compared to the parent training group on IQ, visual–spatial skills, language, school placement and academics (Smith, Groen, ; Wynn, 2000). The ABA treatment group gained an average of 16 IQ points; in contrast, the parent training group lost one IQ point (Smith, Groen, ; Wynn, 2000). Twenty-seven percent of the children in the ABA group achieved average post-treatment scores and were succeeding in regular education classrooms (Smith, Groen, ; Wynn, 2000).
In both 2002 and 2007 Eikeseth, Smith, Jahr, and Eledevik compared effects of ABA and assorted treatments for children with Autism Spectrum Disorders (ASD). Follow-up evaluations were completed approximately three years after the treatment started and revealed the ABA treatment group scored significantly higher as compared to the assorted treatment group on intelligence, language, adaptive functioning, maladaptive functioning and on two of the subscales on the socio-emotional assessment (social and aggression) (Eikeseth, Smith, Jahr, ; Eledevik, 2002; 2007). The ABA treatment group gained an average of 25 IQ points compared to an increase of seven points in the assorted group; 12 points in adaptive functioning compared to an increase of 10 points (Eikeseth et al., 2002; 2007). Follow up evaluation revealed that seven of 13 children in the ABA group who scored within intellectual disability range at baseline, increased their final score to within the average range (85) on both IQ and verbal IQ at follow-up, compared to two of twelve children in the assorted treatment group (Eikeseth et al., 2002; 2007).
Howard, Sparkman, Cohen, Green, and Stanislaw (2005) evaluated the effects of three treatment approaches on children with ASD, including ABA. At the fourteen-month follow-up, their findings indicated the ABA treatment group scored significantly higher than compared to the two comparison groups on all measures. The ABA treatment group gained an average of 31 IQ points and 11 points in adaptive functioning (Howard, Sparkman, Cohen, Green, ; Stanislaw, 2005). The comparison groups obtained average increase of nine points in IQ and two points in adaptive functioning (Howard et al., 2005). Another study of note, conducted by Sallows and Graupner (2005), examined the effects of ABA treatment versus parent managed ABA treatment for children with ASD. At follow-up evaluations, there were no significant differences between groups. All participants increased a mean of 25 IQ points (Sallows ; Graupner, 2005). Forty-eight-percent of all participants in both groups showed faster learning rates, earned average post treatment scores and were finding success in regular education classrooms (Sallows ; Graupner, 2005). Sallows and Graupner’s (2005) findings indicated parents who implement ABA can see growth with their children as well as professionals who implement the program.
Virués-Ortega (2010) reviewed 206 studies to determine if ABA had a significant impact on treating students diagnosed with autism spectrum disorders (ASD). His results showed ABA led to positive effects for children diagnosed with ASD in intellectual functioning, language development, acquisition of daily living skills, and social skills. These promising findings added to the scientific evidence ABA has a positive impact on the lives of children (Virués-Ortega, 2010).
Warren, Veenstra-Vander, Weele, Stone, Bruzek, Nahmias, Foss-Feig, Jerome, Krishnaswami, Sathe, Glasser, Surawicz, and McPheeters (2011) completed a ten-year review of studies published from January 2000 to May 2010 for treatments of students with ASD. Their results revealed there is evidence that supports early intensive behavioral and developmental intervention using programs based on ABA principles, will improve cognitive performance, language skills, and adaptive behavior in some groups of children (Warren et al., 2011).
Chaining: An Introduction
The field of ABA is “much broader and includes a range of tactics, methods, and procedures that have been shown to be effective for many different types of problems” (Hagopian & Boelter, 2005, para. 1). When professionals decide to begin an ABA treatment protocol, it must be determined what behaviors or skills to target and how to achieve the desired goal; one such approach is chaining (Slocum & Tiger, 2011). Chaining procedures can be employed with children and adult clients. Chaining procedures have been used with individuals diagnosed with schizophrenia, intellectual disabilities, autism, attention deficit hyperactivity disorder, developmental disabilities, and pediatric feeding disorders (Hagopian & Boelter, 2005).
A behavior chain is a classification of related behaviors, in which each step provides the prompt for the subsequent step, and the last step produces a reinforcer; Cooper, Heron, and Heward (2007) reported “a behavior chain is a specific sequence of discrete responses, each associated with a particular stimulus condition” (p. 434). According to Cooper, Heron, and Heward (2007), a behavior chain has three hallmark features; first it “involves the performance of a specific series of discrete responses” (p. 436). The second feature of a behavior chain is “the performance of each behavior in the sequence changes the environment in such a way that it produces conditioned reinforcement for the preceding response and serves as an SD for the next response” (Cooper, Heron, & Heward, 2007, p. 436) The third feature is the responses within the chain “must be performed in a specific sequence, usually in close temporal succession” (Cooper, Heron, & Heward, 2007, p. 436).
When implementing chaining procedures, a task analysis must be conducted to separate the chain of target responses into a series of steps to be taught one at a time (Cooper, Heron, & Heward, 2007; Slocum & Tiger, 2011). The steps in the chain are recognized as requirements for mastery; chaining divides a skill into smaller steps and then teaches each step within the sequence by itself with rewards and reinforcement (Cooper, Heron, & Heward, 2007; Slocum & Tiger, 2011).
Cooper, Heron, and Heward (2007) reported chaining could be used to teach students with developmental disabilities; chaining is a good way to teach student independent living skills. As independent living skills develop throughout training, students are more likely to “function effectively in least restrictive environments or participate in activities without adult supervision” (Cooper, Heron, & Heward, 2007, p. 437). Research has indicated that task analysis and chaining have been used to successfully teach complex behaviors such as self-care skills (Horner & Keilitz, 1975; Matson, Taras, Sevin, Love, & Fridley, 1990; Stokes, Cameron, Dorsey, & Fleming, 2004; Wacker & Berg, 1983), vocational tasks (Duran, 1985; Frank, Wacker, Berg, & McMahon, 1985; Maciag, Schuster, Collins, & Cooper, 2000), following picture activity schedules (MacDuff, Krantz, & McClannahan, 1993; Robinson-Wilson, 1977), play skills (Libby, Weiss, Bancroft, & Ahearn, 2008; Luyben, Funk, Morgan, Clark, & Delulio, 1986), personal hygiene (Veazey, Valentino, Low, McElroy, & LeBlanc, 2015).
Historically all forms of chaining have been successfully implemented to improve functional skills of individuals with disabilities. Robinson-Wilson (1977) used chaining procedures and picture sequencing recipe cards to train adults with ID adults to cook independently. Wacker and Berg (1983) found chaining and “picture prompts can be effective in promoting both the acquisition and generalization of complex vocational performance with moderately and severely retarded adolescents” (p. 431). Frank, Wacker, Berg, and McMahon (1985) taught five individuals with ID to complete two different computer tasks. Luyben, Funk, Morgan, Clark, and Delulio (1986) taught three adults with mild intellectual disability (ID) to kick/pass a soccer ball using chaining and prompting procedures. Walsh and Holding (1990) used backward chaining to teach keyboarding skills. Jerome, Frantino, and Sturmey (2007) reported “adults with developmental disabilities can learn both leisure and computer skills using prompting, forward and backward chaining, and differential reinforcement” (p. 185). According to Tarbox, Madrid, Aguilar, Jacobo, and Schiff (2009), “chaining can be used effectively to increase the complexity of echoics in children with autism” (p. 905). Veazey, Valentino, Low, McElroy, and LeBlanc (2015) used total-task chaining to teach feminine hygiene to females with ASD.
Chaining: Forward, Backward, and Total
Once target behaviors or skills have been “constructed and validated and the criterion for success and the data collection procedures have been determined, the next step is to decide which chaining procedures to use to teach the new sequence of behavior” (Cooper, Heron, & Heward, 2007, p. 442). Chaining can be further broken down into forward, total-task, or backward chaining. Using a forward chain, the behaviors or skills identified in the task analysis are taught in a natural progression (Cooper, Heron, & Heward, 2007, p. 442). Total-task chaining “is a variation of forward chaining in which the learner receives training on each step in the task analysis during every session” (Cooper, Heron, & Heward, 2007, p. 442). Backward chaining begins by teaching the final step in the task analysis first and teaching the steps in reverse order; “as earlier steps are added, all previously taught steps and the current step are required to be accurately completed in order to be considered correct and result in reinforcement delivery” (Slocum & Tiger, 2011, p. 793).
Forward, backward, and total-task behavior chains have been “shown to be effective with a wide range of self-care, vocational, and independent living behaviors” (Cooper, Heron, & Heward, 2007, p. 446); however, there have been conflicting reports on the efficacy of backward versus forward chaining. Weiss (1978) compared backward and forward chaining methods. His results indicated participants could complete tasks using both forward and backward chaining methods; however, there was a higher error rate when backward chaining methods were employed (Weiss, 1978).
Slocum and Tiger (2011) reported “there is no consistent difference in task acquisition given instruction consisting of forward or backward chaining between or within participants” (p. 803). Slocum and Tiger (2011) reported “forward chaining was associated with fewer trials to mastery in eight comparisons, backward chaining was associated with fewer trials to mastery in six comparisons, and no difference in trials to mastery was obtained in two comparisons” (p. 802).
Several other researchers have suggested forward chaining is more effective than backward chaining due to the natural progression of the steps involved in teaching the chain (Knerr, Morrison, Mumaw, Stein, Sticha, Hoffman, Buede, & Holding, 1986; Nettlebeck & Kirby, 1976; Walls, Zane, & Ellis, 1981). Spooner and Spooner (1984) reported ”it may be that different learners do better with different procedures, and when different tasks are used, different results are obtainable” (p. 123).
Researchers agree more research is warranted to fully identify which type of chaining procedure works best (Knerr et al., 1986; Nettlebeck & Kirby, 1976; Slocum & Tiger, 2011; Veazey, Valentino, Low, McElroy, & LeBlanc, 2015; Walls, Zane, & Ellis, 1981). Veazey, Valentino, Low, McElroy, and LeBlanc (2015) reported more research needs conducted to “replicate the effects of chaining with participants of varied ages and skill sets and more systematically investigate long-term maintenance of these skills and generalization to novel stimuli and places” (p. 188). Future research should focus on generalization of skills across ages, grades, and ability levels and if skills are maintained without cues (Jerome, Frantino & Sturmey, 2007).
Chaining: The Procedure
All chaining methods follow three basic principles, which include defining the target behavior, reinforcing elements in the chain, and monitoring results (Cohen, 2002; Cooper, Heron, & Heward, 2007). The first step when implementing a chaining procedure is to determine which method of chaining is to be employed. The second step is the completion of a detailed task analysis to determine the steps in the chain (Cohen, 2002; Cooper, Heron, & Heward, 2007). Cooper, Heron, and Heward (2007) reported “the more complete and accurate the task analysis is, the more likely a person will be to progress through the sequence efficaciously” (p. 450). To develop a behavior chain from a task analysis, it is important to remember the complexity of the chain will affect the time to complete training (Cooper, Heron, & Heward, 2007).
When implementing a forward chaining procedure, steps are completed in a naturally occurring progression (Cooper, Heron, & Heward, 2007). “Reinforcement is delivered when the predetermined criteria for the first behavior in the sequence is achieved” (Cooper, Heron, & Heward, 2007, p. 442). Weiss (1978) reported “abundant anecdotal evidence suggests that humans often learn behavior chains by the forward method” (p. 255). Research has demonstrated multiple benefits when forward chaining procedures are used. First, the participants are only taught one link or step in the chain at a time; each step is paired with a reinforcer while the response is being conditioned (Knerr et al., 1986; Nettlebeck & Kirby, 1976; Slocum & Tiger, 2011; Walls, Zane, & Ellis, 1981; Weiss, 1978). When the ABA trainer pairs the targeted step in the chain with reinforcement, there is increased chance for success that the step will be mastered (Knerr et al., 1986; Nettlebeck & Kirby, 1976; Slocum & Tiger, 2011; Walls, Zane, & Ellis, 1981; Weiss, 1978). The second significant benefit to using forward chaining is the simplicity in its implementation; training parents, teachers, and staff to use a forward chain appears to be easier than teaching the chain in a reversed order (Bennett, 2009; Knerr et al., 1986; Nettlebeck & Kirby, 1976; Slocum & Tiger, 2011 Walls, Zane, & Ellis, 1981; Weiss, 1978). Forward chaining has the distinct “advantage of using behavior momentum, as the first step is often the simplest, easiest step” (Meadows, 2011, para. 6).
The steps in a forward chain are as follows:
1. Identify the target behavior
2. Task analyze the behavior to determine each individual step
3. Teach and reinforce the initial step in the skill
4. Collect data on the acquisition of the skill and analyze it for mastery
5. When the first step is mastered, teach and reinforce the second step in conjunction with the first step
6. As each successive step is mastered, add the next step in the skill series until the student is able to demonstrate the entire skill without adult support (Webster, 2017).
When implementing a backward chaining procedure, steps are completed in a reverse progression beginning with the final step of the task analysis (Cooper, Heron, & Heward, 2007). Reinforcement is presented when the “learner performs the final behavior in the sequence at the predetermined criterion level” (Cooper, Heron, & Heward, 2007, p. 443). Researchers recommend using a backward chaining method if the individual can complete multiple steps at the end of the behavior chain as determined by the task analysis (Bennett, 2009). “Backward chaining also has the advantage of creating a link between the most work and the biggest reinforcer” (Meadows, 2011, para. 5).
The steps in a backward chain are as follows:
1. Identify the target behavior
2. Task analyze the behavior to determine each individual step
3. Teach and reinforce the last identified step in the skill
4. Collect data on acquisition of the skill and analyze it for mastery
5. When the final step is mastered, teach and reinforce the next-to-last step (i.e., or the step before the last step)
6. As each successive step is mastered, add the previous step in the skill series until the student is able to demonstrate the entire skill without adult support (Webster, 2017).
Chaining: The Final Breakdown
Baer, Wolf, and Risley (1968) created the formative description of ABA as a discipline, and emphasized ABA is technological, meaning its intervention techniques or procedures are precise, detailed, and replicable. All types of chaining require the implementation of established principles of learning, behavioral strategies, and modifications to the environment to improve and teach replacement behaviors. During implementation, teaching must be systematic so professionals can identify how behavior can be changed and understand how learning occurred (Baer, Wolf & Risley, 1968). The goal of chaining is to establish and enhance socially important behaviors that can include any skill that will enhance the independence or quality of life for the individual (Cohen, 2002; Cooper, Heron, & Heward, 2007; Hagopian & Boelter, 2005; Meadows, 2002; Slocum & Tiger, 2011; Webster, 2017). Chaining is based on science in which interventions are taken from current research and applied to improve behavior in socially significant ways.