Date of Completion


Embargo Period



Kindergarten Vocabulary, Fidelity of Implementation, Early Education, Vocabulary Learning, Tier 1 Vocabulary, Hierarchical Linear Modeling

Major Advisor

Michael D. Coyne, Ph.D.

Associate Advisor

D. Betsy McCoach, Ph.D.

Associate Advisor

Devin Kearns, Ph.D.

Associate Advisor

Sharon Ware, Ph.D.

Associate Advisor

Morgaen Donaldson, Ph.D.

Field of Study

Special Education


Doctor of Philosophy

Open Access

Open Access


Many children start school with significantly lower vocabulary knowledge than their peers. Therefore, providing young students, especially at-risk students, with effective Tier 1 classroom vocabulary instruction is imperative. Current research indicates that teachers can have a significant influence on student literacy and reading achievement, however there is little existing research investigating classroom or teacher effects on students’ early vocabulary learning. The purpose of this study was to examine between-classroom variability in student vocabulary achievement in kindergarten classrooms implementing a common Tier 1 vocabulary curriculum. Specifically, the study examined whether at-risk and not-at-risk students in different classes experienced different vocabulary learning of words taught during instruction, and whether there was differential vocabulary learning between those groups of students. Finally, this study investigated if teachers’ fidelity of implementation of the Tier 1 vocabulary program was associated with the vocabulary learning of at-risk and not-at-risk students and/or the differential learning between those two groups.

Hierarchical linear modeling was used to answer the research questions. Findings revealed that that students in different classes experienced differences in their vocabulary achievement. The results also suggest that both at-risk and not-at-risk students experience different vocabulary learning in different classes. In addition, a trend indicated that at-risk and not-at-risk students in different classes experienced varying levels of vocabulary learning, which

suggests that teachers have different effects on the vocabulary learning of at-risk and not-risk-students.

Finally, the findings of this study suggest that teachers’ fidelity of implementation had a statistically significant effect on the vocabulary learning of at-risk students; that at-risk students are more responsive to teachers with higher level of fidelity. Teachers’ fidelity was also associated with the variability in the differential vocabulary learning between at-risk and not-at-risk students. The results of this study extend the literature on classroom Tier 1 vocabulary instruction as well as the research on teacher effects on early vocabulary learning. Findings reinforce the importance of providing teachers with professional development on early vocabulary learning and instruction, particularly training focused explicitly on the appropriate use of vocabulary programs to ensure high levels of implementation fidelity. Limitations of the current study and directions for future research are also discussed.

Available for download on Saturday, April 18, 2026