Does Growth Rate in Oral Reading Fluency Matter in Predicting Reading Comprehension Achievement? Young-Suk Kim Florida State University and Florida Center for Reading Research, Tallahassee, Florida Yaacov Petscher Florida Center for Reading Research, Tallahassee, Florida Christopher Schatschneider and Barbara Foorman Florida State University and Florida Center for Reading Research, Tallahassee, Florida In this study, we examined the relationship of growth trajectories of oral reading fluency, vocabulary, phonological awareness, letter-naming fluency, and nonsense word reading fluency from 1st grade to 3rd grade with reading comprehension in 1st, 2nd, and 3rd grades. Data from 12,536 children who were followed from kindergarten to 3rd grade longitudinally were used. These children were administered Dynamic Indicators of Basic Early Literacy Skills subtests, Peabody Picture Vocabulary Test—Third Edition, and reading comprehension (Stanford Achievement Test, 10th ed.) tasks multiple times in each year. Students’ initial status and rate of growth in each predictor within each grade were estimated using individual growth modeling. These estimates were then used as predictors in dominance regression analyses to examine relative contributions that the predictors made to the outcome: reading comprehen- sion. Among the 1st-grade predictors, individual differences in growth rate in oral reading fluency in 1st grade, followed by vocabulary skills and the autoregressive effect of reading comprehension, made the most contribution to reading comprehension in 3rd grade. Among the 2nd- and 3rd-grade predictors, children’s initial status in oral reading fluency had the strongest relationships with their reading comprehension skills in 3rd grade. Keywords: DIBELS, dominance analysis, growth rate, oral reading fluency, reading comprehension Since the passing of the No Child Left Behind Act of 2001, the importance of developing students’ reading skills, reading fluency in particular, is at the forefront of discussion (e.g., Roehrig, Petscher, Nettles, Hudson, & Torgesen, 2008). An underlying assumption in this discussion is that students will have differential growth rates in reading development and that variation will matter for their reading acquisition. In other words, because students vary widely in their initial reading skills, students who enter school with limited language and literacy experiences may need to catch up or develop at a faster rate than their peers with more experience. Therefore, not only overall level of skill but also growth rate in critical reading skills should be predictive of later reading achieve- ment. However, despite the presumed importance of rate of growth, it is not clear whether differences in growth rate in important emergent and conventional literacy skills are predictive of later reading comprehension achievement. Emergent literacy skills refer to “the skills, knowledge, and attitudes that are devel- opmental precursors” (e.g., phonological awareness, letter knowl- edge, and concept of print; Whitehurst & Lonigan, 1998, p. 848) to conventional forms of reading and writing (e.g., word decoding skills, oral reading fluency [ORF], and spelling). Examining the contribution of growth rate in emergent and conventional literacy skills to reading comprehension is important for both policy and instructional purposes. From a policy perspec- tive, if variability in growth rate in literacy skills is related to students’ later reading comprehension achievement, it is important to incorporate growth rate into accountability decisions. From an instructional perspective, if the growth rate in literacy skills reli- ably predicts later reading comprehension, teachers may need to frequently monitor growth in order to accommodate to students’ changing needs. However, if overall level of student performance at the beginning of the year plays a critical role in determining students’ achievement at the end of the year or at a later time point, then teachers can primarily utilize assessment information at the beginning of the year to plan instruction for the year. In the present study, we investigated whether and to what extent level of perfor- mance at the beginning of the year (initial status) and growth over time in important literacy skills (e.g., vocabulary, phonological decoding fluency, and ORF) in first, second, and third grades make a contribution to reading comprehension at the end of each grade and third grade. Background and Context In the present study, we used data from a statewide database that includes scores from the Dynamic Indicators of Basic Early Lit- eracy Skills assessments (DIBELS; Good & Kaminski, 2002). Young-Suk Kim and Barbara Foorman, College of Education, Florida State University and Florida Center for Reading Research, Tallahassee, Florida; Yaacov Petscher, Florida Center for Reading Research; Christo- pher Schatschneider, Department of Psychology, Florida State University and Florida Center for Reading Research. Correspondence concerning this article should be addressed to Young- Suk Kim, C234D, Florida Center for Reading Research, Department of Psychology, Florida State University, 1107 West Call Street, Tallahassee, FL 32306. E-mail: ykim@fcrr.org Journal of Educational Psychology © 2010 American Psychological Association 2010, Vol. 102, No. 3, 652– 667 0022-0663/10/$12.00 DOI: 10.1037/a0019643 652 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.