Parents often wonder if their teen should take the SAT, the ACT, or both. The majority of colleges accept scores from either of these two college entrance tests. The SAT is primarily a reasoning test while the ACT measures specific subject knowledge. At http://collegeapps.about.com/od/productreviews/gr/act-or-sat-review.htm you can read a review of a book that includes an assessment for teens to take in order to predict which test might best suit your student.