This handbook is intended to serve as a procedural guide for Utah school districts to improve the assessment and classification process for students who are behavior disordered. The handbook reviews Utah's definition of behavior disorders and explains some of the ambiguous terminology in the definition. The topic of social maladjustment is examined, along with its relationship to the behavior disordered classification. Types of behavior problems most often classified and served in programs for students with behavior disorders are reviewed. Fundamental principles and practices of educational and psychological assessment are presented. Using that as a base, best practices for assessing students who may be classified as behavior disordered are identified. The practices stress the importance of evaluating current instructional conditions, documenting educational and social adaptive behavior, and implementing prereferral interventions. The handbook then concludes with a checklist to be used in making decisions about the classification of students with behavior disorders. Appendixes outline an observation system and list rating scales for school and home behavior disorders and for social skills assessment. (JDD)