This paper considers elementary teachers' perceptions of data-driven decision making (DDDM) through the lens of Dewey's science of education. Dewey argues that educational science can be used to improve teaching and learning, but it must be flexible, attendant to multiple dimensions of growth, and grounded in real classroom experiences with teachers at the helm. Results indicate that teachers have a vision of classroom assessments consistent with Dewey's vision, but often feel inhibited by the constraints of standardized assessments.