University of Michigan Homeschooling study

Question:
the University of Michigan had recently completed a study proving that homeschoolers make higher scores on the ACT and the SAT tests. Have any of you seen the actual results of the test ? Anyone know of where I could get an "executive summary" of the results ?

Answer:
-Please be careful how you use any such study.

There is an inherent problem in studying homeschoolers. Most studies compare the population of "homeschoolers" to the population of "all others."

Unfortunately, this could be the definition of a skewed comparison.

Homeschoolers are more likely to be middle class, more likely to be from a two-parent family, and more likely to be from a family in which the parents emphasize education. All of these things affect test scores positively.

The "other" population, on the other hand, including the public school population includes a much wider demographic group, including a fairly substantial group of student for whom none of the above apply.

Homeschoolers are often members of a population that would do well on tests no matter what.

-I've read three responses, none of which make the following point: The wider group of homschoolers contains those who have been booted or who have otherwise figured out that they don't fit into regular school--the hyperactive, those with emotional problems, ...

Also homeschooling are people who have more tangible educational needs than this. We have friends who are homeschooling their DownS child in order for him to have the best care possible.

I don't dispute that homeschoolers in general might be of a more scholastic bent or otherwise more privledged, but am just making the point that the deck isn't stacked entirely in our favor.