||The purpose of this study was to examine the influence of data use on student achievement. Two research questions were considered: is the use of formative assessment tools (Yearly Progress Pro and Acuity) correlated to student achievement outcomes and are there factors (access to computers, a teacher's level of experience, or school level leadership) that explain greater use of formative assessment tools? To answer these questions, a series of hierarchical linear models were used that allowed for factors to be considered at the teacher and school level. While greater use of both formative assessment tools had a positive effect on student achievement for teachers, there was a statistically significant positive effect when Yearly Progress Pro was used more frequently. When considering factors that influence the use of data, teacher experience and access to computers were not found to be statistically significant influences. However, school-level leadership supporting collaboration had a statistically significant positive influence on the frequency of data use. Greater use of formative assessment tools is positively correlated to student achievement; however, further research is required to develop any causal relationship. Additionally, more specific research looking at the effectiveness of various forms of formative assessment in addition to how these assessments are actually utilized by teachers to inform their classroom practice would be beneficial. School-level leadership is also an important component to encourage greater use of formative assessment data, particularly when teacher collaboration around data use is supported by building principals.