ROBERT E. O'NEILL
The foundation of every positive behavior support (PBS) plan is a functional assessment (also referred to as a functional behavioral assessment). Functional assessment defines a process of gathering a collection of information about an individual and his or her environment. The outcome of a functional assessment is a documentation of events related to problem behavior, as described in the four-term contingency model introduced in Chapter 2. That is, it will define setting events, antecedents, and maintaining consequences related to problem behavior. In addition, it will reveal broad lifestyle issues that need to be enhanced to improve an individual's life in general. This information is essential for identifying effective and efficient ways to reduce undesirable behavior, increase desirable behavior, and ensure a good quality of life.
Because effective and enduring behavior support plans include multiple components and address all areas of an individual's life, the assessment information must be comprehensive. Specifically, it should document both historical and current events, and should reveal issues both immediately and peripherally related to challenging behavior. In addition, information that is derived in various ways (e.g., through interviews, record reviews,