A nonrandomized quasi-experimental, mixed-method double pretest-posttest design was used to compare the effects of a multilinguistic word study model of instruction -- RAVE-O program (Wolf, Miller, & Donnelly, 2000) -- in comparison with a phonics word study model of instruction -- Fountas and Pinnell Phonics Lessons -- Letters, words, and how they work (Pinnell & Fountas, 2003). Repeated measures data were collected over 12 weeks, reflecting three points in time (i.e., Time 1: Fall pretest -- baseline to Time 2: April pretest to Time 3: June posttest) to examine 50 first-grade students' growth in word reading and spelling. Additionally, the linguistic patterns of spelling errors were examined across approaches. It was hypothesized that first-grade students who received explicit multilinguistic word study instruction would demonstrate greater literacy achievement (i.e., word reading and spelling) than first-grade students receiving traditional phonics word study instruction. It was also hypothesized that the linguistic pattern of spelling errors (i.e., phonological, orthographic, transpositions, and morphological) would differ as a function of the instructional approach. Neither proposed hypothesis was confirmed in this study. Data showed an overarching pattern of achievement in which, for most outcomes, children demonstrated growth in word reading and spelling skills regardless of the word study approach. More extensive examination of spelling (i.e., correct words, feature points, and inflected endings) revealed significant growth over time for all spelling outcome measures -- including morphological comprehension and use, regardless of the word study approach. The linguistic categories of spelling error types on multimorphemic words from least to most were transposition, orthographic image, phonological, orthographic, with the most frequent errors being morphological errors. Students in both groups demonstrated significant growth from pre- to post-testing on their ability to provide the correct affix (i.e., prefix or suffix) when spelling multimorphemic words (i.e., unable, return, giving) -- even if they were unable to spell the word correctly. While neither proposed hypothesis was confirmed in this study, the results showed that multilinguistic word study instruction could produce comparable results to traditional phonics word study instruction. This study also reinforced that children in the primary grades can access and use varying linguistic resources and processes, including higher-level morphological knowledge in their reading and spelling development. Furthermore, this study supported the position that examining instruction in the primary grades that incorporates metalinguistic information and a greater understanding of oral and written language versus waiting until the upper grades warrant further examination. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]