Fred refuses to speak at school, although he speaks normally at home. his therapist plans out a treatment where fred is given a gold star every time he answers his teacher, and he can then trade in his stars for prizes. fred begins speaking in class. the therapist then tells the teacher to stop the program for a couple of weeks. fred stopped talking during that time. the teacher then starting giving fred stars again, and fred again began to talk. this is an example of

a. a case study.
b. a correlational study.
c. an abab experimental design study.
d. a self-report study.

The best option is c. an ABAB experimental design.

Explanation:

ABAB research design, also called withdrawal or reverse design, aims to observe if a treatment is being effective by exposing the subject to treatment, observing the results, then once again exposing to treatment, and confirming (or not) the results. The first A is the establishment of a steady baseline. The first B, then, is the introduction of the treatment. After the second baseline has been measured during B, the treatment is withdrawn during the second A. Again, having the baseline measured, the second B is the reintroduction of the treatment. That is precisely the method used with Fred to see how he responds to the reinforcement to speak.

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