Standards

The ESSA tiers of evidence are closely aligned to the standards of the What Works Clearinghouse (WWC), an investment of the Institute of Education Sciences (IES) within the U.S. Department of Education. In fact, outcomes only qualify for ESSA tiers 1 and 2 if they meet WWC standards (with, or without reservations, respectively). The WWC standards are updated periodically and can be browsed by the public on the IES website:

To stay closely aligned to the non-regulatory guidance for ESSA, the ERC relies on evidence reviews against the standards of the WWC to assign suggested ESSA tiers and populate our clearinghouse. Reviews of research studies against these standards may be conducted by What Works Clearinghouse itself, or by other professional research organizations. Per our research process, those organizations help determine if the study meets WWC standards, and also determine the ESSA tiers of the study outcomes.

For reviews of studies by What Works Clearinghouse-certified reviewers and for ESSA tier verifications, the ERC contracts with American Institutes for Research (AIR), one of the world's largest behavioral and social science research and technical assistance organizations and a leader in ESSA-related resources and professional development.

www.air.org

To use resources efficiently, if another professional, independent research organization has assigned a WWC rating and an ESSA tier to an outcome for an educational strategy, the ERC may publish that rating without conducting our own separate review.