Data can be powerful when educators have the ability to interpret and respond to them in ways that promote positive changes in teacher behavior and classroom/program environments. At the heart of the process lies the need for a school-wide culture of collaborative inquiry that fosters open and honest dialogue. Making effective use of data includes a thoughtful selection from multiple sources of information, systematic data collection, analysis and dissemination, and the intentional application of findings to ongoing changes to instructional practice and policy.