A large, nationwide survey in 1998 of home-schoolers in kindergarten through 12th grade found they scored higher in student achievement tests compared to public and Catholic/private school students.
Students taught at home have also scored above the national average composite score for the ACT college-entrance exam every year since 1997.
In 2004, the average score for home-schoolers was 22.6. In the last eight years, scores for home-schoolers have not fallen below 22.5, while the scores nationally dropped from an average of 21 in 1997 to 20.8 in 2003 and 20.9 in 2004.

http://desmoinesregister.com/apps/pbcs.dll/article?AID=/20041213/NEWS02/412130313