What is Chaining?
Chaining is an instructional strategy grounded in applied behaviour analysis (ABA) theory. Chaining is a type of intervention that aims to create associations between behaviours in a behaviour chain. A behaviour chain is a sequence of behaviours that happen in a particular order where the outcome of the previous step in the chain serves as a signal to begin the next step in the chain. Chaining breaks a task down into small steps and then teaches each step within the sequence by itself.
Chaining is based on task analysis, in which individual steps are recognized as requirements for task mastery. Chaining is used to teach complex behaviours made of behaviour chains that the current learner does not have in their repertoire. Various steps of the chain can be in the learner’s repertoire, but the steps the learner doesn’t know how to do have to be in the category of can’t do instead of won’t do (issue with knowing the skill not an issue of compliance).
There are three different types of chaining which can be used and they are forward chaining, backward chaining, and total task chaining (not to be confused with a task analysis). One of the methods is selected based on the nature of the task or the skill levels of the child.
Forward Chaining
Forward chaining is a procedure where a behaviour chain is learned and completed by teaching the steps in chronological order using prompting and fading. The learner emits the first step in the behaviour chain, and the instructor completes the rest of the sequence.
Once the learner meets mastery criteria for the first step in the sequence, they are taught to complete the first two steps and the instructor completes the remaining steps. Reinforcement is delivered for completion of the step, although they do not attain the terminal reinforcer (outcome of the behaviour chain) until they are prompted through the remaining steps.
Let’s use an example: we want our children to learn to brush their teeth.
This requires a series of actions that take place in a specific order. In forward chaining, children first learn the first step of the process. In this case, children are rewarded for applying toothpaste to their toothbrush.
Then the adult completes the rest of the steps. Over time, further steps are added in sequence. For example, brushing the upper teeth, brushing the lower teeth, brushing the molars, spitting out, rinsing, etc.
Adults only reinforce the last step the child is working on. Once a child has learned the steps up to brushing their teeth, there is no point in continuing to reward them.
Total Task Chaining
Total task chaining is a type of forward chain.
Each time the behaviour sequence or complex task is presented, the instructor teaches every step in the sequence. This gives the learner an opportunity to practice each step, every time.
Backward Chaining
Backward chaining is the procedure that is typically used for people with limited abilities. This process uses prompting and fading techniques to teach the last step first. Backward chaining refers to teaching a behavioural chain beginning with the last step: you would completely prompt the entire chain of behaviours except the last step.
The biggest benefit of using a backwards chain is that the learner receives the terminal reinforcer (the outcome of the behaviour chain) naturally. Backward chaining is the preferred method when teaching skills to individuals with severe delays because they complete the last step and see the direct outcome of the chain immediately rather than having to be prompted through the remaining steps to receive that reinforcement.
For example, if you want your child to clean up after playing, you can put away the toys yourself, except for one piece. Then let your child pick up the last toy and reward this behavior.
The next day your child puts away two toys and the day after that, three toys. This continues until your child is fully responsible for cleaning up all the toys. The beauty of this option is that children start much closer to the goal, or in other words, to success. This can make motivation seem greater from day one.
How can chaining be applied?
To use chaining, you first have to determine the steps of a task. This process is called a task analysis. How to determine the steps of a task? Here is how:
- Watch someone complete the task
- Write down the steps of the task
- Have someone else perform the task using the steps you have written
- Make adjustments to the steps as needed
- Present the task to the student or watch the skill performance in the natural setting
- Take data on student performance with each step of the task
- Based on data, decide which chaining techniques to use
The steps in forward chaining:
- The student is encouraged to complete the last step independently.
- When the last step is mastered, the teacher provides assistance until the child is able to perform the step before the last one.
- The student completes more and more ending steps independently until he masters all steps and is able to complete the task without assistance.
The steps in backward chaining:
- The teacher teaches the child the first step in the chain.
- When the first step is learned, the teacher adds the second step. The child is learning the second step in the routine and attaching it to the first step.
- The third step is taught in conjunction with the first two steps once the child is able to demonstrate the first two steps.
The steps in total task presentation (when the student attempts all steps of the chain):
- The teacher teaches the child the first step in the chain.
- When the first step is learned, the teacher adds the second step. The child is learning the second step in the routine and attaching it to the first step.
- The third step is taught in conjunction with the first two steps once the child is able to demonstrate the first two steps.
For whom it can be used?
Teaching a skill using chaining is commonly recommended if the child can only perform some of the steps, consistently misses/skips steps, or is completing steps incorrectly. This technique is helpful in assisting children to learn a routine task that is repetitive, such as using the bathroom, brushing teeth, putting on clothes and shoes, or completing a work task.
McNiven & Blevins (2016) argued that Chaining is identified as being effective for preschoolers (3-5 years) when addressing communication and joint attention skills and middle school-age learners (12-14 years) to address social, communication, and joint attention, academic, motor, and adaptive skills.
Previous use of chaining with children with ASD.
Chaining is a methodology that has been applied in many different scenarios and also tested for different disorders. For example, McHugh (2019) used the techniques to compare a modified version of a commonly used treatment, food chaining, and an empirically validated ABA treatment to treat the food selectivity of 2 children with autism spectrum disorder (ASD). For both children, consumption of the target foods only increased during the ABA-treatment condition. They subsequently faded the size of the preferred food within the simultaneous-presentation arrangement, moved to a sequential-presentation arrangement, and then thinned the schedule of reinforcement. (McHugh, 2019)
In addition, Lee et al., (2019) did an experiment with six children between the ages of 6 and 10 with a primary diagnosis of moderate MR. They were randomly assigned to either a forward or a backward chaining group. A single-subject ABA design was used to examine the effects of each intervention technique. Dressing skills were assessed pre and post intervention using the Self-Care section of the Pediatric Evaluation of Disabilities Inventory (PEDI). The findings showed a significant improvement in the skill of dressing for all participants in both the forward and backward chaining intervention groups. The results suggest that both forward and backward chaining methods can be effectively used to teach children with moderate MR dressing skills. The use of one-on-one interaction, physical and verbal prompts, as well as positive reinforcements may have facilitated the success of these interventions. (Lee et al., 2009).
Finally, Tarbox, et al., (2013) looked at echoics and language intervention for children with autism, because a well-established echoic repertoire on the part of the child allows the clinician to use vocal modelling as a flexible, low-effort prompting procedure during teaching. In this study, we implemented a chaining procedure to increase the complexity of echoics in 2 children with autism and 1 child with developmental delay. The procedure was effective for all 3 participants, and gains were maintained after treatment was withdrawn in most cases. (Tarbox, et al., 2013)
Conclusion remarks
The disadvantage of this method is that the supplemental reinforcers at every step need to be diminished as the child acquires the skill. This means that developing a chain can be quite time consuming. However, the results are long-lasting and very important for the daily lives of the ABA patients.
References
Lee, C.S. Brianne, E.M., Osborne, N.L. 2009. The Effect of Chaining Techniques on Dressing Skills of Children with Moderate Mental Retardation: A Single-Subject Design Study. Journal of Occupational Therapy, Schools, & Early Intervention. Vol2 (3-4). 178-192. https://doi.org/10.1080/19411240903392590
McHugh, C. (2019). A Comparison of Modified Food Chaining and Simultaneous Presentation Plus Nonremoval of the Spoon to Treat Food Selectivity in Children with Autism Spectrum Disorder. M.A. Applied Disability Studies. http://hdl.handle.net/10464/14085
McNiven, L. & Blevins, P. (2016). Effects of Applied Behavior Analysis on individuals with Autism. https://gcd.state.nm.us/wp-content/uploads/2018/05/Effects_of_Applied_Behavior_Analysis_on_individuals_with_Autism.pdf
Tarbox, J., Madrid,W. Aguilar, B., Jacobo, W., Schiff, A., Ninness, C. (2013). Use of Chaining to increase Complexity of Echoics in Children With Autism. Journal of Applied Behavior Analysis. Vol. 42 (4).901-906. https://doi.org/10.1901/jaba.2009.42-901
Internet Sources
https://www.unl.edu/asdnetwork/virtual-strategies/chaining
https://howtoaba.com/behavior-chain-in-aba/
https://behaviorbubbles.home.blog/2019/10/17/chaining/
https://www.iloveaba.com/2013/09/backward-forward-chaining.html