Practitioners often employ therapeutic interventions with their clients without a systematic method for evaluating the effectiveness of such procedures. This is typically due to the imprac‐ticalities of true experimental designs in the clinical setting. The authors present a case in which multimodal therapy is applied to an aggressive preadolescent in a high‐management residential setting. Methods of data collection, analysis, and interpretation are demonstrated using a single‐subject accountability model. A practical and usable method of determining the clinical significance of multimodal therapy is emp