How Do the SAT Subject Tests Differ from the SAT?

The SAT is largely a test of verbal and math skills. True, you need to know some vocabulary and some formulas for the SAT; but it's designed to measure how well you read and think rather than how much you remember. The SAT Subject Tests are very different. They're designed to measure specific knowledge in particular academic areas like Physics or World History. Sure, critical reading and thinking skills play part on these tests, but their main purpose is to determine exactly what you know about, math, history, physics, and so on.