One day an eleventh grader named Marie Pasteur sits down at her desk and takes an SAT II Chemistry practice test. Because it makes this example much simpler, imagine she takes the entire test and gets only one question wrong.

The question Marie missed dealt with mitosis. Because she doesn’t have the best grasp on mitosis, she mistakenly thought that anaphase preceded metaphase, when it’s the other way around. So she takes a few minutes to study up on cell reproduction and sorts out when the different phases take place and what happens in each. All this takes about ten minutes, after which Marie vows never again to miss a question involving mitosis.

Marie wasn’t content simply to see what the correct answer was and get on with her day; she wanted to see how and why she got the question wrong and what she should have done, or needed to know, in order to get it right. She spent a little time studying the question, discovered her mistaken understanding of mitosis, and learned the subject thoroughly. If Marie were to take that same test again, she definitely wouldn’t get that question wrong.

Skeptical readers might say, “But she’ll never take that test again, and she’ll never see that particular question again, so wasn’t figuring out her mistake a waste of time?”

No! It’s definitely not a waste of time. If you take the time to learn why you got a question wrong and to learn what you need to know to get it right, you’ll probably remember what you learned the next time you’re faced with a similar question. And chances are excellent that you will be faced with a similar question.

So what if you take a practice test and get 15 questions wrong, and your errors span many of the major topics in biology? Do exactly what Marie did. Take your test and study it. Identify every question you got wrong, figure out why you got it wrong, and then teach yourself what you should have done to get the question right. If you can’t figure out your error, find someone who can.

A wrong answer on the SAT II Chemistry identifies a weakness in your test taking, whether that weakness is an unfamiliarity with a particular topic or a tendency to be careless. As you study each wrong answer, you are actually learning how to answer questions that will appear in similar form on the real SAT II Chemistry. You are discovering your exact weaknesses and addressing them, and you are learning to understand not just the knowledge behind the question, but also the way that ETS asks questions.

True, if you got 15 questions wrong, studying your first practice test will take some time. But if you invest that time and study your practice test properly, you will be eliminating future mistakes. Each successive practice test you take should have fewer errors, meaning you’ll spend less time studying those errors. More importantly, you’ll be pinpointing what you need to study for the real SAT II Chemistry, identifying and overcoming your weaknesses, and learning to answer an increasing variety of questions on the specific topics covered by the test. Taking practice tests and studying them will allow you to teach yourself how to recognize and handle whatever the SAT II Chemistry throws at you.