Abstract
Public Law 94–142 mandates special educational placement decisions based on multidisciplinary and multifaceted assessments. Nevertheless, some diagnostic data have significantly greater impacts upon the decision-making process than others. Four samples—20 school psychology graduate trainees, 20 special education trainees, 20 school psychology practitioners, and 20 special education practitioners—independently rated 16 pieces of diagnostic data on their importance in determining a student's special educational placement. Results indicated that classroom observation, assessments of expressive and receptive language, an interview with the referred child, and emotional indicators were most important to the decision. There were no significant differences between the ratings of the four samples.