The purpose of this study is to examine the relationship between a teacher's expertise, instructional practices, belief about assessment, use of assessment, and student achievement. There is minimal and sometimes conflicting research to support the relationship between teacher characteristics and student achievement. For the present study, teacher information was collected on a survey administered to a random sample of 1100 kindergarten through third grade teachers throughout the state of Virginia. A total of 284 usable surveys was returned. Archived data from the Phonological Awareness and Literacy Screening (PALS) assessment administered to kindergarten through third grade students in Virginia were used as the measure for student achievement. Correlational analysis was utilized to determine the relationship between student gains on literacy assessment (PALS) and the following constructs: teacher's beliefs about PALS, teacher's comprehension, phonological awareness, and fluency instructional practices, teacher's use of assessment data, teacher's educational background and experience, and teacher's professional development experiences. In addition to correlational research, multiple regression analysis was used to determine if any factors had greater predictive value on gains in student achievement. The current study found correlations between gains in student achievement at different grade levels for the following constructs under investigation: instructional practices, certification as a reading specialist, professional development, personally administering PALS, using ongoing assessment, and parent communication. Gain scores were positively correlated with specific instructional practices in kindergarten, yet were inversely related to level of education. Publishing was correlated in first grade, however, participation and presenting at conferences was negatively correlated. At second grade, teachers who reported that PALS had a positive effect on their teaching showed a negative relationship to gain scores. Finally, in third grade, certification as a reading specialist and use of data were positively correlated to gains in student achievement. Most correlations were weak except for the practice of teachers personally entering their PALS scores onto the website. No factors were found to have greater predictive value on gain scores than any other factor. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]