The SAT may be a better test for you if:
1. You did great on the PSAT. The devil you know may be better than the devil you don't.
2. You have a killer vocabulary. You know "didactic," "sedulous" and other esoteric words (including esoteric) and want to use that comparative advantage.
3. You can ace grammar. In addition to the essay section, the Writing section of the SAT tests the deviation between standard written English and the way we actually speak the language.The ACT may be a better test for you if:
1. You did great on the PLAN (the "PSAT" for the ACT) or had a PSAT or SAT score inconsistent with your academic performance in school.
2. Your vocabulary is not as strong as your reading. You read well and relatively quickly. Arguably, the ACT is a test that is three parts verbal — English, Reading and Science (the latter section requires no knowledge outside of what the test presents).
3. You are great at writing papers but haven't had formal grammar instruction.Excerpted from http://www.npr.org/templates/story/story.php?storyId=7535849
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