Journal of Autism and Developmental Disorders, Vol. 27, No. 5, 1997 Brief Report: Interrater Reliability of the Psychoeducational Profile (PEP) Peter Muris1 Limburg University, Maastricht Pim Steerneman Community Mental Health Centre, Eastern South-Limburg, The Netherlands Elise Ratering Medical Centre for Preschool Children, Heerlen, The Netherlands. INTRODUCTION The psychoeducational profile (PEP; Schopler & Reichler, 1979; Schopler, Reichler, Bashford, Lansing, & Marcus, 1990) is an instrument that can be used for the assessment of children with pervasive develop- mental disorders, ranging in age from 1 to 7. PEP results can be employed to design an individually tailored educational and treatment program (e.g., Shopler, Mesibov, & Baker, 1982). On the one hand, the PEP provides information concerning several important domains of the child's develop- ment (e.g., imitation, perception, motor activity, language, and cognition). On the other hand, the PEP yields an index of the severity of disturbed behaviors which are commonly observed in children with pervasive devel- opmental disorders. No information about the interrater reliability of the PEP is currently available. Although, as mentioned above, the PEP is used to develop an individually tailored educational program, there are some conditions under which interrater reliability might be important (Parks, 1988). For example, in clinical practice, the PEP is regularly used as a measure to determine treatment efficacy. When different experimenters are involved in pre- and 1Address all correspondence to Peter Muris, Department of Experimental Abnormal Psychology, Limburg University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. 621 0162-3257/97/l000-0621S12.50/0 c 1997 Plenum Publishing Corporation