Tanabe, Maura Elizabeth Doyle2012-11-262012-11-262012-08https://hdl.handle.net/11299/139684University of Minnesota Ph.D. dissertation. August 2012. Major: Educational Psychology. Advisors:Scott R. McConnell, PhD, Amanda Sullivan, PhD. 1 computer file (PDF); xi, 155 pages.Data-based decision making is at the forefront of educational research, policy, and practice (Barnett, Bell, & Barnett, 1999; Barnett, VanDerHeyden, & Witt, 2007; NCLB, 2001). While the practice of using data to make decisions about children with disabilities has been a part of early childhood special education services, there have been limitations to the usefulness and meaningfulness of these data (McConnell, 2000). One aspect of this is the lack of quality tools with which to make decisions. The goal of this study was to further evaluate the potential of one such tool for preschool children with disabilities to assess expressive language growth. The Pre-Elementary Education Longitudinal Study (PEELS), a large national dataset, provided a unique opportunity to further the validity-related evidence and usefulness of the Picture Naming–Individual Growth and Development Indicator (PN–IGDI) for a larger and broader sample of children with disabilities. The purpose of the study was twofold: (1) to examine validity-related evidence (e.g., construct-related validity, predictive-related validity) and usefulness of the PN–IGDI and (2) to determine if disability category (i.e., Autism spectrum disorder, developmental delay, or speech or language impairment) influenced these results. Results provided continued support for the validity-related evidence for the PN–IGDI for children with language-related disabilities. In particular, the predictive-related validity evidence showed a promising relationship between the PN–IGDI and the Dynamic Indicator for Basic Literacy Skills Oral Reading Fluency (DIBELS ORF). Further establishing its usefulness, the PN–IGDI was sensitive enough to detect change over time for children with disabilities. However, evidence from this study did not indicate that there were substantial differences in how well the PN-IGDI measures expressive vocabulary among the disability groups. The merits, limitations, and directions for future research were also discussed.en-USEarly literacyIGDIThesis or Dissertation