Identifying and Implementing Educational Practices Supported by Rigorous Evidence: A User-Friendly Guide Share Close Share Why is Facebook not here? Why is Twitter not here? Share on LinkedIn Share on Google Plus Permalink Email December 1, 2003 Source: U.S. Department of Education U.S. Department of Education acknowledges the strength of class size research evidence. NEPC Legacy Resource Document Expand Download Print Share Share PDF: Why is Facebook not here? Why is Twitter not here? Share on LinkedIn Share on Google Plus Email Download or Print Permalink Copy Link Embed PDF: Copy Embed Code