Functional Behavior Assessments are a necessary assessment for students with intensive behavior needs.   We need to be able to determine the function of the behavior in order to find appropriate replacement behaviors, consequences, or antecedent strategies.  Behaviors that are defined on the FBA need to be measurable and observable – the definitions need to be so clear that ANYONE who picks up the definition should be able to observe the individual and know whether or not the problem behavior is occurring or not occurring, and when it starts and ends.  In the video it states that your team should come up with a consensus as to what the function of the behavior is.  I think it is good to have a hypothesized function that is supported by data, but that you really need to manipulate different variables to figure out exactly what the function of the behavior is.  Perhaps the student is getting attention and escaping from work at the same time, if you guess wrong and say it is attention that is maintaining the behavior the student could still be escaping work and the behavior would continue to be reinforced.  For the organization that I work with, a formal FA done by a BCBA with direct observations is ideal.  We also wouldn’t explain the function or have student input because of the functioning level of the students that I work with.  I think that this is a good starting point but that for severe problem behaviors a formal FA would be necessary.  Once you are confident in the function of the behavior, a hypothesis can be formulated, but not until then.  Replacement behaviors can then be selected, keeping in mind the student’s current repertoire.  Making the replacement behavior easier and more efficient that the problem behavior in gaining access to reinforcement is what aids in decreasing the behavior, in addition to putting the problem behavior on extinction.   I think that RESA has a good tool to aid in the process of determining the problem behavior and building a behavior support plan, it just isn’t the exact process that I am used to.