Assessment is a complex function requiring an understanding of student learning, assessment principles, practices, and purposes of data to implement effective classroom assessment. The purpose of this study was to add to the growing base of knowledge about teachers' engagement with assessment data and their motivation for classroom assessment. Four full-time elementary schoolteachers in diverse teaching contexts in Alberta and Ontario, Canada, participated in semistructured individual interviews. The results from this study settled into four main categories: (1) teachers use for learning assessment to improve student achievement, (2) an imbalance of formative assessment--assessment as learning was not used consistently, (3) inconsistent formalization of observation into meaningful assessment data, and (4) the tension between internal and external motivators for student assessment.