4.3: ABC’s of Function-Based Supports

A function-based support plan should include components that (a) address antecedent triggers to prevent problem behavior, (b) teach alternative and desired behaviors, and (c) identify appropriate responses to desired and problem behaviors. Figure 4.10.1 illustrates the A-B-C sequence and how function plays a pivotal role in designing prevention strategies, teaching alternative or replacement behaviors, and responding to both desired and problem behaviors. In Figure 4.10.1, antecedents are defined as events or stimuli that immediately precede or trigger problem behavior. Behavior is the observable behavior of concern (i.e., problem behavior). Consequence is defined as the consistent response to the problem behavior that reinforces the behavior. This logic is based on applied behavior analytic literature (e.g., Horner, 1994), suggesting function is where problem behavior intersects with the environment to affect learning. Given this logic, an individual exhibiting problem behaviors has learned: “Within a specific situation ‘X’ (context), when ‘A’ (antecedent is present) if I do ‘B’ (problem behavior), then ‘C’ (the maintaining consequence) is likely to occur.” Through experience and repetition, the individual learns that the problem behavior is effective or “functional” for meeting their needs. Therefore, the individual is likely to continue to engage in the problem behavior under similar circumstances. Based on this model, the function of an individual’s behavior should guide the selection of each component intervention (prevention, teaching, and consequence strategies) within a positive behavior support plan.