In July 2009, CREDO (Center for Research on Education Outcomes) published a national report on charter school achievement. The Center for Education Reform and Dr. Caroline Hoxby, among others, have critiqued the report’s results and methodology:

A Statistical Mistake in the CREDO Study of Charter Schools
A report from researcher Caroline M. Hoxby explaining the statistical mistake in the CREDO report on charter school achievement.

Understanding Charter Achievement Research: The CREDO Report
CER provides brief talking points on the 2009 CREDO report on charter school achievement across 15 states and the District of Columbia.

Fact-Checking Charter School Achievement
Why some are saying only 1 in 5 charter schools perform, and why it’s wrong. Insight on the widely cited CREDO study.

CER Summary Hoxby New York Charters 2009
The most comprehensive study on charter school achievement at the time of the 2009 CREDO study comes from Caroline M. Hoxby and demonstrates quality charter school research methodology.

 
The Center for Research on Education Outcomes continues to research charter school achievement in various states. Below you will find analysis on some of the CREDO state reports:

New Jersey
CER’s research team breaks down differences between the controversial 2009 report and the New Jersey charter school achievement report.

Michigan
New state-level studies demonstrate more rigorous standard of research than national study.