During independent work time, Ms. Lee observed Craig and Benjamin repeatedly engage in the same disruptive offtask and talking-out behaviors. In the past, when her students engaged in misbehavior, she reminded them of the rules and then, if the behavior continued, she often changed their seating arrangement. Sometimes this worked and other times it did not. But in the case of Craig and Benjamin, their misbehaviors continued. For both students, talkingout behavior looked and sounded similar (i.e., verbal comments unrelated to the task), but the talking out seemed to be maintained by different reasons. When Craig talked out peers interacted with him, and when Benjamin talked out it typically delayed or reduced the amount of time he spent working on assigned tasks. Ms. Lee needed a different approach to managing these students' behavior. Before the development of functional behavior assessment (FBA), intervention for students' problem behaviors often included arbitrarily selected reinforcers and harsh punishments that were devised to overpower whatever else might be maintaining the behavior. In sum, teachers relied on the assumption that strong enough consequences would eventually change behavior, regardless of what underlying function that the behavior might be serving (E. G. Carr, 1977). Advancements in the assessment and treatment of problem behavior have improved treatment outcomes by focusing on the selection and implementation of interventions based on the function, or the purpose, that a behavior serves for the individual (Gann, Ferro, Umbreit, & Liaupsin, 2014; Geiger, Carr, & LeBlanc, 2010). The FBA process leads to a hypothesis of function by identifying patterns of environmental events that occur prior to and following problem behavior. That is, FBA identifies both when a behavior is likely to occur and what changes in the environment make it likely to continue occurring. Once the function is identified, treatment is designed to rearrange and disrupt the environment in ways that make appropriate behavior more likely and problem behavior less likely (O'Neill et al., 1997). As mentioned, the concept of function refers to why the student engages in the behavior or the payoff to the individual for engaging in the behavior. Common functions typically fall into two specific categories: those that provide access to desired outcomes (positive reinforcement) and those that provide escape or avoidance of undesirable outcomes (negative reinforcement). When reinforcement occurs, something is either added (positive reinforcement) or removed (negative reinforcement) from the environment, thereby making the behavior more likely to occur in the future (Cooper, Heron, & Heward, 2007). For example, a student may talk out because it results in peer attention (positive reinforcement) or because it makes the teacher take the focus off of boring instruction (negative reinforcement). In both these examples, the consequence following problem behavior reinforces or strengthens the behavior. In either case the behavior will contin...