A reversal design can be used to show that a given therapeutic treatment (e.g. psychotherapy, drug treatment, etc…) is a predominant cause of a change in a patient’s behavior. The logic of this design is fairly straightforward; it could be described as a BTB design. A baseline behavior, or set of behaviors, (B) is first measured by the researcher, then a treatment condition (T) is presumed to change the behavior. In order to confirm that the change in behavior was, mostly, due to the treatment, the researcher measures the baseline behavior again to confirm that the treatment is reversible. If the second measure of the baseline is similar to the original baseline measure, it can be assumed that the change from the baseline measure to the treatment measure was due to some aspect of the treatment (Horner et al., 2005). Since a reversal design involves repeated measures of behavior in a given setting, it allows for not only prediction and verification, but also allows for …show more content…
ABAB designs (Bordens & Abbott, 2008). An ABAB design uses the same three steps of the ABA design along with a fourth step of re-introducing the treatment; this allows for further assessment of changes in the target behavior. This design allows researchers to establish the internal validity of their study through intra-subject replication; by testing the treatment condition twice, researchers can verify that an effect is stable and can be replicated within each subject. An example of a reversal (ABAB) design is an experiment assessing wandering in people with dementia. Heard and Watson (1999) looked at four participants with dementia and, in the first phase, took a baseline reading of how often they wandered over the course of 6-9 sessions. Next, a differential reinforcement of another behavior (DRO) operant schedule was used as a treatment; it coincided with a decrease in wandering (in each patient) over the course of 8 sessions. After that, DRO was eliminated, and the participants’ level of wandering returned to baseline over the next 6 sessions. Finally, a second implementation of DRO took place, and the participants’ wandering once again decreased over the last 6 sessions of the experiment (Heard & Watson, 1999). This experiment showed not only that continuous DRO treatment is sufficient for attenuating the wandering symptoms of dementia; it demonstrated that the DRO procedure did not lose its ability to