Functional behavior assessment (FBA) is an integral component of treatment development for students with intellectual and developmental disabilities. The continuum of FBA methods includes indirect, direct, and functional analysis assessment methods. However, there is not a standard for the best approach to the FBA process. This evaluation compared the results of an indirect, direct, and functional analysis assessment method including an analogue and embedded functional analysis approach. The participants included three elementary aged participants with autism in a special education self-contained classroom. The results of this study indicated partial agreement across assessment methods for all participants which varied across participants. The inclusion of an embedded functional analysis into the student's typical classroom schedule provides important information about the ecological validity of functional analysis assessment methods. All assessments were conducted across the day to account for the possibility of the change in function and multiply maintained behavior, as functions may shift as the establishing operation changes across the day. Implications for the results of each FBA method are discussed along with implications for future research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]