In this study, the implementation of Accelerated Reader (AR), a computer-assisted supplemental reading program, was investigated as a research-based instructional strategy to assess whether it aided a high-performing, rural school district in meeting adequate yearly progress goals. The theoretical framework was based on Vygotsky's zone of proximal development. The overall research question for this quasi-experimental, longitudinal study was whether AR impacted students' reading change scores on a standardized test over a 2-year period. Reading achievement data of students in 4 elementary schools were gathered for 2 years. Data consisted of scores from the reading portion of the Measures of Academic Progress achievement test. Seventy-four students from 2 schools participated in AR for 2 years, while the control group--72 students from 2 other schools--did not participate in AR. Data were analyzed using multiple regression, controlling for the effects of gender, special education status, gifted and talented education participation, Title I participation, and English language learner status. Findings showed the AR program had a significant direct impact on vocabulary score changes from 2009 to 2010 but a significant inverse impact on overall reading and vocabulary score changes from 2010 to 2011. Because the district under study is relying on AR to improve student outcomes, the project for this study was an evaluation report including an evaluation of the effectiveness of AR. An action plan was also provided to investigate the level of AR program fidelity to identify possible reasons for this study's unexpected results. Positive social change implications include providing research-based data to school administration to inform curriculum and professional development and improve student outcomes and school performance targets. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]