Single-subject research is a cornerstone of ABA. It provides the means for a behavior analyst to measure the change in behavior for a single client when an intervention is introduced. But how do you know if your intervention is working? You might ask the client or his/her parents or teacher, but that may not be an accurate reflection of actual behavior change.
In order to have reliable evidence of behavior change, you must use some form of repeated, systematic measurement of the target behavior before, during, and after the intervention. That way, you can best assess the impact of the intervention on the target behavior. These systematic measurements are called single-subject design, and they follow a few simple and basic rules. The first and most important is repeated measurement using a consistent observation technique. And you must do this across baseline and intervention phases, at a minimum.
One particular type of single-subject design is reversal design. Reversal design adds a phase after the baseline and intervention phases. This additional phase removes the variable responsible for the intervention, continuously measuring the subject to see whether behavior reverts in the direction of baseline levels.
This week‘s Discussion focuses on reversal designs. For this Discussion, you will analyze the strengths and weaknesses of reversal designs, and you will examine practical and ethical considerations of this single-subject design method.
To Prepare
- Review the Learning Resources for this week as well as the required weekly media programs, to gain an understanding of the types of single-subject designs and when each is appropriate. Note: It is critical for you to review all media for this week prior to completing this Discussion.
- Next, focus on reversal designs and their implementation.
- Consider the following example for your initial Discussion post:
Reversal designs (e.g., A-B-A-B designs) require the removal of an intervention to help you determine if the intervention is working. Using the graphic prototype of an A-B-A-B design (see Figure 8.1 in your Cooper et al. text), assume the target behavior is making eye contact and the intervention is contingent praise (e.g., “Nice job looking me in the eye.”).
- Based on the example, consider why you might remove an intervention that is working. Next, consider ethical issues with removing treatment from a client to examine the efficacy of the intervention.
- Post an explanation of practical and ethical considerations related to using reversal design with the target behavior in the example. Provide an additional example of a target behavior for which using a reversal design would be ethically inappropriate.
Resources
- Cooper, J. O., Heron, T. E., & Heward, W. L. (2020). Applied behavior analysis (3rd ed.). Pearson.
- Chapter 8, “Reversal and Multielement Designs” (pp. 171–192)
- Chapter 9, “Multiple Baseline and Changing Criterion Designs” (pp. 193–215)
- Alnahdi, G. H. (2015). Single‐subject designs in special education: Advantages and limitations. Journal of Research in Special Educational Needs, 15 (4), 257–265. doi:10.1111/1471-3802.12039 Single-subject designs in special education: advantages and limitationsLinks to an external site.
- Rvachew, S., & Matthews, T. (2017). Demonstrating treatment efficacy using the single subject randomization design: A tutorial and demonstration. Journal of Communication Disorders, 67 , 1–13. doi:10.1016/j.jcomdis.2017.04.003 Demonstrating treatment efficacy using the single subject randomization design: A tutorial and demonstrationLinks to an external site.