The Home Situations Questionnaire-PDD version: Factor structure and psychometric properties M. Chowdhury, 1 M. G. Aman, 1 L. Scahill, 2 N. Swiezy, 3 L. E. Arnold, 1 L. Lecavalier, 1 C. Johnson, 4 B. Handen, 5 K. Stigler, 3 K. Bearss, 2 D. Sukhodolsky 2 & C. J. McDougle 3 1 Nisonger Center – UCEDD The Ohio State University, Columbus, Ohio, USA, 2 Yale Child Study Center,Yale University, New Haven, Connecticut, USA, 3 Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA, 4 Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA 5 Department of Psychiatory, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Abstract Background The Home Situations Questionnaire (HSQ) is a caregiver-rated scale designed to assess behavioural non-compliance in everyday settings that has been used in several studies in typically developing children. Currently there is no accepted measure of behavioural non-compliance in children with pervasive developmental disorders (PDDs). Methods Investigators of the Research Units on Pediatric Psychopharmacology Autism Network modified the HSQ for children with PDDs by adding five items (making  total items), and used it as the primary outcome measure in a clinical trial. In the current investigation, we examined the factor structure and psychometric properties of the modified scale, the HSQ-PDD. Results An exploratory factor analysis with oblique rotations yielded two factors: ‘Socially Inflexible’ ( items) and ‘Demand-Specific’ (six items). Item content of both factors appeared to fit well with the rubric of PDDs. Internal consistency, using Cron- bach’s alpha statistic, was . for ‘Socially Inflexible’, and . for ‘Demand-Specific.’ The obtained sub-scales and HSQ-PDD Total score showed moderate correlations with selected sub- scales of the Aberrant Behavior Checklist, Child and Adolescent Symptom Inventory, and Children’s Yale-Brown Obsessive Compulsive Scale, and low correlations with the Vineland Adaptive Behavior sub-scales. Conclusions The HSQ-PDD appears to be well suited for children with PDDs, although the Demand-Specific sub-scale may benefit from addi- tion of more items.We provided sub-scale means and standard deviations for this relatively severe group of children with PDDs, and discussed the factor structure with respect to previous research. Keywords autism, behavioural non-compliance, factor structure, Home Situations Questionnaire, pervasive developmental disorder Introduction The original Home Situations Questionnaire (HSQ; Barkley & Edelbrock ) was developed to examine the severity of disruptive and non- compliant behaviour in children with disruptive Correspondence: Ms Monali Chowdhury,  Dodd Drive,  McCampbell Hall, Columbus, OH , USA (e-mail: chowdhury.@osu.edu). Journal of Intellectual Disability Research doi: 10.1111/j.1365-2788.2010.01259.x     pp –   281 ©  The Authors. Journal Compilation ©  Blackwell Publishing Ltd