In this review, I examined the last two decades of research on data use in education to outline the ways in which principals used data to inform their own leadership practices. I found three themes: first, student achievement data were the most widespread form of data that principals used; second, principals' work has been reshaped by teacher…

Data use has become a priority in educational systems throughout the world under the belief that rational instructional decisions can be tailored to individual learner needs. Despite increasing expectations for school principals to be instructional leaders, there is little evidence that they -- or other system or school leaders -- are responsible…