One critical component of single subject designs is the notion of experimental control. That is, researchers want to be able to document that it is the intervention which they are using which is causing the changes in the target individual’s behavior. The approaches are therefore designed to prove the interventionist’s experimental control. Although this goal is probably not paramount in the teacher’s mind (as long as the behavior is improving in the desired direction), it is at the same time helpful to know what it is exactly that is causing the observed change in a student’s behavior. So, although teachers may not go to the extremes that a researcher might to document experimental control, it still has utility for them as well.

Regarding experimental control, the teacher might be fairly confident that the final approach was the reason the student succeeded, however, not completely sure. It could be that it was the order in which the approaches were applied, or some other confounding variable. Your instructor remembers a student he had who was extremely disruptive. Using a changing conditions design, many approaches were attempted, all to no avail. Finally a different strategy (who knows what it was) was attempted and the behavior improved dramatically. Approaching the student, your instructor gloated, "I’m glad to see your behavior is coming under control." The student, oblivious to the gloating responded, "Yeah, my dad told me that if he got one more phone call from the school, he was going to shoot me like a dog, and I believe he would." The gloating stopped and the realization was made that the reason why students improve may have nothing directly to do with the interventions being applied by the teacher.

You can email Dr. McNair at jmcnair@calbaptist.edu

Copyright Jeff McNair/jeffmcnair.com