Despite the wide usage of Conners' 10-item Abbreviated Parent-Teacher Questionnaire (APTQ), normative data for parental ratings on the APTQ are rare. Moreover, its psychometric properties as a "stand alone" behavioral rating instrument have yet to be examined in detail. Using data from parental ratings for 6,841 children aged 5 to 14 years, this paper reports the psychometric properties of the APTQ and provides normative and prevalence estimates for four age cohorts (5 to 6, 7 to 8, 9 to 11, and 12 to 14 years) by gender. In presenting the findings, the paper highlights key methodological issues endemic to the design of behavioral rating inventories like the APTQ and the analysis of data derived from them. These issues are illustrated and discussed in terms of their implications for the measurement and determination of prevalence estimates of problem behaviors in child psychology and child psychiatry. The need to revise the design, content, and response formats of child behavior rating inventories is stressed.