Since the onset of NCLB legislation and federal funding for schools tied to summative assessment performance, educational leaders have sought to identify factors that are most influential on student learning outcomes. Research continues to link the use of formative data practices and teacher efficacy to improved student performance. The intent of this study was to explore associations between teacher capacity and attitude and student performance. In this embedded mixed-methods study, qualitative data from focus groups comprised of survey participants were collected within a larger quantitative study that examined associations between teacher beliefs and student performance. The study focused on the impact of teacher beliefs on learning outcomes. Participants included elementary math and/or reading teachers at four elementary schools in a large, urban school district. Perceptual survey data were collected regarding teacher beliefs about their capacity to use MAP data and their attitudes towards MAP data. These data were compared to student proficiency and growth scores obtained on MAP in both math and reading using Pearson product-moment correlation. Focus group data were collected from each site in order to explain trends in survey responses. This study introduced teacher attitude as a new construct within teacher efficacy that was compared to both student proficiency and growth on the MAP assessment. Correlations for the relationships between teacher perceptions and student performance ranged from 0.24 to 0.46 (capacity) and 0.23 and 0.65 (attitude), with the highest correlational relationship between teacher attitude and student growth. Recommendations from the researcher include addition of teacher attitude as a separate construct within teacher efficacy and additional professional learning within the site of the study. [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.]