A trial-based functional analysis (TBFA) offers several advantages beneficial for classroom settings. TBFA can be completed rapidly, requires fewer resources than traditional functional analyses (FAs), can occur in the natural environment during typically scheduled activities, and involves less intense data collection methods. However, a number of areas remain to be explored including whether TBFA can be applied to populations beyond those with developmental disorders and whether modifications typically employed in traditional FAs (e.g., idiosyncratic functions) can be applied to TBFA. The present study built upon existing research by completing TBFA with a student identified with an emotional behavioral disorder (EBD), modifying conditions to explore idiosyncratic variables that may be responsible for problem behavior, and including the classroom teacher during the TBFA.