xv, 109 p. : col. ill. / The current study investigated variability in student performance on DIBELS Oral Reading Fluency (DORF) Progress Monitoring passages for third grade and sought to determine to what extent the variability in weekly progress monitoring scores is related to passage-level factors (e.g., type of passage [i.e., narrative or expository]), readability of the passage, reading rate for words in lists, passage specific comprehension, background knowledge, and interest in the topic of the passage) and student-level factors (e.g., the student's initial skill and variability across benchmark passages). In light of recent changes in IDEIA legislation allowing for the use of Response to Intervention models and formative assessment practices in the identification of specific learning disabilities, it was intent of this study to identify factors associated with oral reading fluency that, once identified, could potentially be altered or controlled during progress monitoring and decision-making to allow for more defensible educational decisions. The sample for analysis included 70 third grade students from one school in Iowa. Results of two-level HLM analyses indicated significant effects for background knowledge, interest in the passage, type of passage, retell fluency, readability, and word reading, with type of passage and readability demonstrating the largest magnitude effects. Magnitude of effect was based upon a calculation of proportion of reduction in level 1 residual variance. At level 2, initial risk status demonstrated a significant effect on a student's initial oral reading fluency score, while the benchmark variability demonstrated a significant effect on a student's growth over time. Results demonstrate support for readability as an indicator of passage difficulty as it relates to predicting oral reading fluency for students and suggest that consideration for the type of passage may be warranted when interpreting student ORF scores. Additionally, results indicated possible student-level effects of variables such as background knowledge and word list that were not investigated within the current study. Limitations of the study, considerations for future research, and implications for practice are discussed. / Committee in charge: Roland Good, Chairperson/Advisor; Laura Lee McIntyre, Member; Joe Stevens Member; Robert Davis, Outside Member; Scott Baker, Member