Most experts stress the importance of taking practice exams when you’re preparing for the MCAT. That’s why it’s best to choose a prep book that offers as many practice tests as possible. Subject reviews are important, but many students focus too much on review because they believe they need more in-depth knowledge of the science topics than they actually do. Practice exams not only give you a sense of your progress as you study, but they also help you understand the type and depth of knowledge the MCAT tests.