What Works Clearinghouse General Disclaimer and Statement

The What Works Clearinghouse (WWC) provides educators, policymakers, researchers, and the public with a central and trusted source of scientific evidence of what works in education. It is important to note the WWC does not endorse particular interventions, nor does it conduct field studies. Rather, the WWC gathers available evidence on particular educational interventions and provides reviews of existing evidence against our standards.

Viewers are permitted to download WWC Reports for duplication without requesting copyright permission. The WWC does request that authorship be noted in the case of reproduction. Viewers are asked to contact individual study authors for permission to duplicate original studies, as these studies are not the property of the WWC.

The What Works Clearinghouse is funded by the U.S. Department of Educations' Institute of Education Sciences and is managed by Mathematica Policy Research, Inc. The views expressed on this website do not necessarily reflect the views of the U.S. Department of Education.