A Multitrait (ADHD–IN, ADHD–HI, ODD Toward Adults, Academic and Social Competence) by Multisource (Mothers and Fathers) Evaluation of the Invariance and Convergent/Discriminant Validity of the Child and Adolescent Disruptive Behavior Inventory With Thai Adolescents G. Leonard Burns Washington State University Chris Desmul Com Score, Inc. James A. Walsh University of Montana Chatchawan Silpakit Mahidol University Phapruke Ussahawanitchakit Mahasarakham University Confirmatory factor analysis was used with a multitrait (attention-deficit/hyperactivity disorder— inattention, attention-deficit/hyperactivity disorder— hyperactivity/impulsivity, oppositional defiant dis- order toward adults, academic competence, and social competence) by multisource (mothers and fathers) matrix to test the invariance and convergent/discriminant validity of the 5-factor model between mothers’ and fathers’ ratings of Thai adolescents (Year 1: n = 872; Year 2: n = 903; Year 3: n = 700; Year 4: n = 984) with the Child and Adolescent Disruptive Behavior Inventory (G. L. Burns, T. Taylor, & J. Rusby, 2001). The results showed equality of like-item loadings, intercepts, and residuals, as well as like-factor variances, covariances, and means between mothers’ and fathers’ ratings within each of the 4 yearly samples. In addition, the between-parent factor correlations showed convergent and discriminant validity with the within-parent factor correlations, showing discriminant validity for each year as well. These results for Thai adolescents and similar results (G. L. Burns et al., 2008) for mothers’ and fathers’ ratings of Brazilian, Thai, and American children provide broader support for the construct validity of the scale. The confirmatory factor analysis invariance and convergent/discriminant validity procedure with multiple sources is considered to provide a much more sophisticated procedure to evaluate the construct validity of attention-deficit/hyperactivity disorder and oppositional defiant disorder rating scales than a single-source approach. Keywords: attention-deficit/hyperactivity disorder, oppositional defiant disorder, measurement invariance, convergent/discriminant validity, agreement between mothers’ and fathers’ ratings Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) rating scales are critical to research on ADHD and ODD. The scales are used as part of the diagnostic process and to measure the effectiveness of treatments. In addition, the scales are important in the search for unique external correlates of the ADHD— inattention (ADHD–IN), ADHD— hyperactivity/impulsivity (ADHD–HI), and ODD symptom dimensions (e.g., causes, risk fac- tors, associated features, and prognosis). Given their important role in increasing our understanding of ADHD/ODD, it is essential that the scales have excellent construct validity. Although confirmatory factor analysis (CFA) provides useful information on the construct validity of an ADHD/ODD rating scale when a single source rates each child’s behavior (i.e., load- ings of the items on their respective factors and the discriminant validity among the ADHD–IN, ADHD–HI, and ODD factors; see Burns, Walsh, Boe, Sommers-Flanagan, & Teegarden, 2001), a more powerful evaluation of a scale’s construct validity occurs with multiple raters. Within a multitrait (e.g., ADHD–IN, ADHD– HI, and ODD) by multisource (e.g., mothers and fathers) frame- work, CFA can first determine if the same symptoms have equiv- alent loadings, intercepts, and residuals between raters—as well as if the same latent symptom dimensions have equivalent variances, covariances, and means between raters. If all the parameters are G. Leonard Burns, Department of Psychology, Washington State Uni- versity; Chris Desmul, Com Score, Inc., Seattle, Washington; James A. Walsh, Department of Psychology, University of Montana; Chatchawan Silpakit, Department of Psychiatry, Mahidol University, Bangkok, Thai- land; Phapruke Ussahawanitchakit, Faculty of Accountancy and Manage- ment, Mahasarakham University, Mahasarakham, Thailand. We thank Yuphayao Roumrot for her assistance with the study and the Demonstration School in Mahasarakham, Thailand for making the research possible. Correspondence concerning this article should be addressed to G. Leo- nard Burns, Department of Psychology, Washington State University, Pullman, WA 99164-4820. E-mail: glburns@wsu.edu Psychological Assessment © 2009 American Psychological Association 2009, Vol. 21, No. 4, 635– 641 1040-3590/09/$12.00 DOI: 10.1037/a0016953 635