incorrect information in text books like they are pushing in Texas. If some of this is from the new "charter" schools and/or voucher schools who are teaching bullshit history and science to todays students, then I would expect lower scores such as these.

I know this wasn't tested, but if you take home schooled kids who were taught that the world is 6000 years old, then they are going to fail the science and archeology sections. And I would also think they fail in biology and chemistry. They will not be college ready.