AN ITEM RESPONSE THEORY ANALYSIS OF THE CONNERS TEACHERS RATING-SCALE

We used an item response theory (IRT) measurement model to examine the 28-item Conners Teacher's Rating Scale (CTRS) for the diagnosis of at tention-deficit/hyperactivity disorder (ADHD). Using an Israeli sample of 453 pairs of respondents (parents and teachers), we broke down our sample into nonclinical (n = 306) and clinical (n = 147) subsamples. IRT analyses based on a rating scale model revealed structural inadequ acies involving the apparent inappropriateness of the 4-point Likert-t ype scale used by the CTRS. Additionally, IRT analyses were able to sh ed light on differences in the structure of the latent trait for the A DHD variable as measured by the CTRS for all four groups of respondent s. Implications for the diagnosis and treatment of ADHD are presented.