WHAT IS A FUNCTION-BASED CLASSIFICATION SYSTEM? The characteristics of a function-based diagnostic classification system are the following (Cipani, 1994):
ll Diagnosis of behavior problem characteristics, not child characteristics ll Prescriptive differential treatment derived from a differential diagnosis ll Assessment data collected provides information on context variables, not just rate of
behavior ll Assessment phase concludes with diagnosis phase, in which a function-based category
is selected that best fits the problem behavior’s putative function under the specific EO
Diagnose Behavior, Not Client A function-based diagnostic classification system examines the contextual nature of the problem behavior. It does not presume that the exhibition of behavior is driven by characteristics inherent in the client or child. This sharply contrasts with the current psychiatric approach to diagnosing client behavior (e.g., Diagnostic and Statistical Manual of Mental Disorders [5th ed.; DSM-5]). In a function-based diagnostic classification system, the form of the behavior (in many cases) does not dictate a particular function.
Let us say you have three different children with whom you are involved as a behavioral consultant. Each child engages in a topographically (form) different set of target behaviors. In the traditional psychiatric diagnostic system, each child may receive a different diagnosis because the form of the problem behaviors is different. Because the behaviors or symptoms are different, their presumed cause is assumed to be different. In contrast, a function-based classification of the problem behaviors may reveal that the problem behaviors exhibited by these three children are similar in function, even though topographically dissimilar. Therefore, the classification of these behaviors function using the Cipani BCS could be the same. Using this hypothetical example, let us presume that the functional behavioral assessment obtained data that indicates that all three children’s behavior produces the same reinforcer (i.e., access to tangible reinforcers such as preferred activities). Hence, the function-based diagnosis for all three sets of problems might be subsumed in the same major category. Therefore, despite the obvious individual differences between these children, the prescription for behavior- analytic treatment for this problem area will be similar in composition.
Prescriptive Differential Treatment As just alluded to, a function-based diagnostic classification system also has implications for differential prescriptive treatment. The behavioral intervention designed takes into consideration the function of the problem behavior(s). It is the case that different topographies.
The Cipani Behavioral Classification System of behavior displayed by a given client can produce the same behavioral contingency if their function is the same. Here is an example.
A child diagnosed with a DSM-5 criteria of Oppositional Defiant Disorder is referred for a number of behavior problems. These problem behaviors include aggressive behavior toward residential staff, noncompliance, and running away from the facility. Aggression, noncompliance, and running away are topographically dissimilar behaviors. Does that mean that different behavioral contingencies should be invoked, depending on which behavior is exhibited at a particular time? Not in the least! If all three behaviors are found to serve the same environmental function, the treatment program would specify the same contingency across the occurrence of any of these behaviors. In other words, irrespective of which behavior occurs, the contingency it would produce (according to the functional treatment plan) would be the same. However, if noncompliance and running away serve a different function than the child’s aggressive behavior, there would be one treatment contingency for aggression and a different contingency for the other behaviors. The specifics of the behavioral treatment are driven by the function of behavior, not by the traditional diagnosis (such is actually irrelevant for functional treatment).
The same behavioral intervention would also apply if different clients or students engage in different forms of problem behaviors, but such behaviors serve the same function. Here is an illustrative example. A child named Susanna, diagnosed with conduct disorder, hits the teacher. A different child named Billy, diagnosed with oppositional defiant disorder, throws a tantrum during class and refuses to follow even simple directions. A third child, Raul, who is diagnosed with attention deficit hyperactivity disorder (ADHD), cries and throws a tantrum when he is prevented from running out of the classroom. Professionals who use a traditional diagnostic classification system presume that each of these three children exhibit different types of behaviors because of their different diagnostic classification. Susanna hits her teacher (and others) because of her affliction with conduct disorders. Billy throws a tantrum because he has oppositional defiant disorder. Raul cries and throws a tantrum because he is impulsive and is incapable of delaying gratification because of his ADHD. If there are three different disorders, should there not be three different treatments, that is, one for ADHD, one for conduct disorders, and so on? Our answer: Not if the different types of behaviors serve the same function (Cipani, 2014)!
Let us say that Raul’s tantrum behaviors and Susanna’s hitting behavior occur when they are denied access to a preferred activity. Both problem behaviors often result in getting the desired activity for each child. Given the same function, the behavioral treatment would be the same. If Billy’s topographically dissimilar problem behaviors are found to produce escape from the task, then the treatment would be designed that addresses that function. But it would be different because of the different function involved (i.e., access vs. escape), not the hypothesized mental disorder! Research studies in applied behavior analysis have failed to demonstrate that certain behavioral procedures work only for children with conduct disorder, or oppositional defiant disorder, and not for those with ADHD, and vice versa.1
In summary, classifying problem behaviors according to environmental function does make a crucial difference in the design of a functional behavioral treatment. In contrast, differential diagnosis using the traditional psychiatric Diagnostic and Statistical Manual of Mental Disorders does not prove fruitful in determining functional behavioral treatments based on syndromes of behaviors.
Assess Context Variables It should now be clear that a useful Functional Behavioral Assessment is concerned with more than just determining the rate of the target behavior. Assessment is driven by the need to determine the environmental factors that are present when the problem behavior occurs, that is, the social and physical environmental context. The effects of both antecedent and consequent conditions of the problem behavior need to be considered. Understanding the role of the client’s antecedent motivational condition at the time makes for a clearer picture of why certain consequent events function as reinforcers at those times. Understanding how certain people may be discriminative for such functions is also important (i.e., socially mediated functions).