A closer look at the Autism Behavior Checklist: discriminant validity and factor structure.

The psychometric properties of the Autism Behavior Checklist (ABC; Krug, Arick, & Almond, 1980a, 1980b), a 57-item screening checklist for autism was investigated. Professional Informants completed the ABC on 67 autistic and 56 mentally retarded and learning-disabled children. The autistic children were the total population of autistic children aged 6-15 in two circumscribed suburban and rural regions. Using the total score, the ABC accurately discriminated 91% of the children, with 87% of the autistic and 96% of the nonautistic group correctly classified. Moreover, the accuracy of classification was virtually identical when only the more heavily weighted checklist items were used. A 3-factor model accounted for 32% of the total variance in the checklist. Seventeen items loaded .4 or more on Factor 1, 12 items loaded on Factor 2, and 10 items loaded on Factor 3. The present results fail to provide empirical support for a single unidimensional scale for autism. Also, there is little support for subdividing the checklist into five subscales based on symptom areas.