The ACT (American College Test) is a 3 1/2 hour test (scheduled several times throughout the year) that satisfies the same basic requirements as the SAT. But unlike the SAT, the ACT is more content-based, including higher-level Mathematics as well as Science Reasoning, which is not found on the SAT. The ACT is comprised of 4 sections: English (primarily in-context grammar), Mathematics, Reading and Science Reasoning. Time-lengths range from 35 minutes to 60 minutes per section, making this a grueling experience for the ill-equipped test-taker. There is also an optional essay at the end of the test for those who feel it may be part of their college's requirements. Scoring on each section is 0-36, with 21 generally considered the equivalent of an SAT score of 520. Every major college and university in the United States will accept the ACT in lieu of an SAT score -- some even prefer the ACT. But though the tests are similar in nature, there are distinct differences that favor certain students over others. The ACT, for instance, is more ideally suited for academically-proficient students, those who don't want psychology to be a factor in the test-presentation. On the other hand, many prefer the SAT and its avoidance of a Science Reasoning section. The best advice is for students to take both the SAT and ACT to see which yields the better score.