When we go to the doctor for a medical test, often we want to know whether we “have” or “do not have” a particular medical condition. For example, the patient wants to know if he has cancer, COVID-19, or strep throat. The expected answer is either “yes” or “no.” Sure, some medical tests are more accurate than others, and any test might be wrong some of the time. But, still, they seem useful in the medical profession.
Now in behavior analysis, we sometimes act as if we are doing something similar to medicine. We are testing for the presence vs. the absence a behavior (or a cause of a behavior), and those results are used to make decisions. In reality, we just about never do that.
In behavior analysis, we can certainly demonstrate the presence of behavior or causes of a behavior. For example, we might do assessments and show that a student can label all his colors, washes her hands, or engages in problem behaviors in order to escape instructional demands.
But unlike the medical profession, in behavior analysis, there is no way to demonstrate that the absence of a behavior means that the behavior never occurs, or that a behavior in a learner’s repertoire it is never caused by a certain event. That’s because there always may be a situation that we haven’t tested where the learner engages in the behavior.
Understanding this is one key to avoiding misleading data and making poor decisions. For example, a common problem I’ve observed is that a BCBA starts working with a learner and conducts an initial assessment of skills. After intervention, a reassessment shows that the child has mastered hundreds of new skills very quickly. Now, that might be the case–sometimes. But it’s more likely that the child already had many of those skills in his or her repertoire. He just didn’t demonstrate them on the initial assessment due to problem behaviors or other reasons. Now that the team has improved problem behaviors and attention, the child has the opportunity to demonstrate many more skills.
In a similar manner, people will argue that a behavioral assessment demonstrated that a child does not have problem behavior motivated by attention since the assessment showed the behavior only occurred under escape conditions. That’s just silly, especially if you consider how this is typically tested. What happens is a child is left with little to do, then an adult (often unknown to the child) pretends they are busy. If the child engages in any problem behavior, the adult provides a reprimand. Of course, a child might not engage in any problem behaviors under those conditions, but still be the class clown when all the other kids are laughing at his antics in the classroom. That’s one reason I don’t do these types of assessments any longer. Greg Hanley and colleagues have demonstrated a better way.
In Behavioral Assessment, we can show that a behavior or cause of a behavior does occur. But we always must be careful about stating that a behavior doesn’t occur. All you really know is that under the circumstances you tested, the behavior doesn’t occur. That’s a critical difference, and misunderstanding this point leads to bad treatment decisions.