As the quality of educational outputs has been problematized, accountability systems have driven reform based upon summative assessment data. These policies impact the ways that educators use data within schools and subsequently, how teacher education programs may adjust their curricula to teach data-driven decision-making to inform instruction. This study explores the outcomes of an instructional intervention that taught data understanding, comprehension, and data use with preservice teacher candidates. The intervention was based on the premise that using data for professional purposes is becoming a necessary proficiency for teacher education graduates and that teacher education curricula must explicitly address that need. Pre-service teacher candidates participated in a Data Chat where they collaboratively analyzed standardized testing and end-of-course assessment data and structured instructional interventions based upon determined strengths and weakness areas in student learning. Data were collected from two academic years. The results from Year 1 suggest that pre-service teacher candidate participants perceived an expanded sense of comfort with the data literacy behaviors (DLBs) following the intervention. Year 2 results validated the earlier finding of perceptions of self-efficacy with using summative assessment data and also identified specific DLBs needing more attention. Implications of the intervention for teacher education are discussed.