Exploratory and confirmatory factor analyses of the DIAL-3: What does this “developmental screener” really measure? Jason L. Anthony ⁎ , Mike A. Assel, Jeffrey M. Williams University of Texas Health Science Center at Houston, Division of Developmental Pediatrics, 7000 Fannin Street, Suite 2377, Houston, TX, 77030, United States Received 16 May 2006; received in revised form 23 January 2007; accepted 12 February 2007 Abstract To examine the convergent and discriminant validity of the scales on the Developmental Indicators for the Assessment of Learning—Third Edition [DIAL-3; Mardell-Czudnowski, C., and Goldenberg, D.S. (1998). Developmental indicators for the assessment of learning—third edition. Circle Pines, MN: American Guidance Service, Inc.], exploratory and confirmatory factor analyses were performed on randomly selected subsamples of 2012 children who attended Head Start. Exploratory factor analysis yielded three factors, labeled Verbal Ability, Nonverbal Ability, and Achievement, which collectively accounted for 56% of the variance in children's performances. Confirmatory factor analysis evaluated this empirically-derived model and the conceptually-derived model of the authors of the DIAL-3 in a separate subsample of children. Although neither model explained the data extremely well, the empirically-derived model characterized children's performances better than the conceptually-derived model, e.g., CFIs = .90 and .85, RMSEAs = .07 and .10, respectively. The discussion highlights an alternative conceptualization of the DIAL-3, potential uses of the factor scores, ideas for consideration during the next revision of the DIAL-3, and the need for additional validity research. © 2007 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved. Keywords: Developmental screening; Preschool; Assessment Journal of School Psychology 45 (2007) 423 – 438 ⁎ Corresponding author. E-mail address: Jason.L.Anthony@uth.tmc.edu (J.L. Anthony). 0022-4405/$ - see front matter © 2007 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jsp.2007.02.003