Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Educational Psychology and Special Education

First Advisor

Laura D. Fredrick

Second Advisor

Paul A. Alberto

Third Advisor

Robin D. Morris

Fourth Advisor

Phill Gagne

Fifth Advisor

Ann C. Kruger


Students with moderate intellectual disabilities (MoID) typically are not taught decoding skills because they have difficulty mastering critical blending skills. In response to this skill deficit among students with MoID, an Initial Phonics instructional sequence was created that included student development of rapid and automatic retrieval of taught letter-sound correspondences to a level of mastery before teaching the skill of blending. For each of 16 students with MoID (ages 6-15), mastery criterion of letter-sound automaticity phases was determined by their individual naming speed as measured by the Rapid Object Naming (RON) subtest of the Comprehensive Test of Phonological Processing (CTOPP). Visual analysis of graphically displayed single-case data revealed a functional relation between simultaneous prompting procedures and letter-sound correspondences, automaticity, and blending acquisition for all students. Furthermore, the use of hierarchical linear growth modeling (HLGM) revealed statistical significance for: (a) the impact of daily instruction on the development of letter-sound correspondences, automaticity, and blending in terms of average student growth per instructional session, (b) variability between student growth trajectories within automaticity and blending phases, (c) student pretest scores on RON as an explanatory variable for differences between growth trajectories within automaticity treatment phases, and (d) the extent to which the number of sessions to mastery within automaticity phases and student age predicted acquisition of blending skills. The purpose of identifying explanatory/predictor variables was to classify cognitive predictors for students with MoID who successfully acquire blending skills.