Version 3.0 of the What Works Clearinghouse (WWC) Handbook is now available for public comment.
The WWC is the Department of Education's web-based repository of evidence on the effectiveness (or lack thereof) of educational interventions. One great thing about the WWC is that the evidence is evaluated for quality using the formal criteria set forth in the Handbook.
Well, if this counts as a public comment: I wonder why they are so insistent on random assignment. Not because I like confounded observational studies but because I think the real added value in RCTs is in the "C." The "R" might be needed for ethical or political reasons only, or laziness to stratify.
ReplyDeleteSee Max Kasy's argument: http://scholar.harvard.edu/files/kasy/files/experimentaldesign.pdf