The manual examines issues in determining eligibility criteria for students with serious emotional disturbance (SED). Educational and clinical definitions of SED are compared, components of the educational definiton are examined, and the issue of differentiating behavioral disorders from serious emotional disturbance is considered. The assessment process for students with SED is then delineated, including educational history; description of previous interventions; developmental and health history; teacher, child, and parent interviews; home visits; behavioral observations; language development; basic skills; and emotional functioning. A final chapter considers the use of criteria from the Diagnostic and Statistical Manual of Mental Disorders in the identification and diagnosis of SED children. Appended are a list of the agencies participating in the criteria project and a list of behavioral characteristics identified by the agencies as comprising evidence of serious emotional disturbance. (CL)