The junior year in high school is fraught. It’s the most important year in terms of academics. It’s when you take the SAT or ACT, when you start putting together your college list, and when you are likely hitting your peak in whatever sports or extra-curricular activities you’re involved in. In short, it’s probably the most stressful year you’ll experience until after you’ve graduated from college.

Into that mix, you need to add often poorly understood SAT subject tests. While most people have at least heard of the SAT, the ACT, or even both, a surprising number of people aren’t even aware that the SAT Subject Tests exist, and even those who do know aren’t sure whether they need to take them, or when, or which ones.

So without further ado, here’s your introduction to the SAT Subject Tests:

What Are The Subject Tests?

The Subject Tests are a series of one hour exams that focus on a variety of academic subjects. They ask multiple choice questions and produce a score on a scale of 200 to 800. For more details and a list of subjects, check out this page on the College Board website.

Do I Need to Take Subject Tests?

This is the first question a lot of people have. The answer is: It depends on where you’re applying to school. Here is a list of schools that require, recommend, or will consider SAT Subject Tests. If you plan to attend to any school that requires or recommends the Subject Tests, you should absolutely take the required (or recommended) number of tests. Make sure you examine the actually stated policy of each school; this list is really just a starting point. For example, many engineering schools require both the Math 2 and one of the Science tests.

Also, some schools don’t require Subject Tests if you take the ACT, so if you plan to take the ACT, you should look into that policy at the schools you’re considering.

When Should I Take Subject Tests?

First of all, in a perfect world, you’d be asking me this question freshman year. Why? Because, depending on the subject, freshman year might be the best year to take the test. You should take a Subject Test at the end of the academic year that you complete the relevant coursework. Interested in taking Biology? If your coursework in Biology is freshman year, that’s when you should take the test.

All other things being equal, you should try to have at least a first crack at the Subject Tests by the end of your junior year; a lot of students save the June test date for exactly that purpose.

Two other important considerations: Subject Tests are given on the same days as the SAT (except the March test date, which is SAT only), so make sure to plan appropriately. Also, the language tests with listening are only given in November. Make sure you plan ahead accordingly.

Which Tests Should I Take?

Obviously, you want the tests that will make the best impression. What does that mean?

1. If the school has particular requirements (or even recommendations), follow them. Some schools require particular tests (usually the Math Level 2 and/or a Science for engineering programs). Other schools require that your two tests be from different “areas" (the areas are usually defined as math, science, humanities, and foreign language). In short, make sure you’re aware of any particular requirements.

2. Math Level 1 usually doesn’t fly at top schools. If you’re applying to one of the very top schools, the Math Level 1 will be considered a real weakness. Only take it if you have no other options.

3. Consider the message you want to send. Your choice of subject tests defines your academic strengths. Math + Science sends a very different message than Language + Literature, though both define you as a specialist. Want to show breadth? Go for Math or Science + Language/Literature/History.

4. Showcase your strengths. The bottom line is that you want to take the tests that will produce that best scores for you. This should trump most other considerations (except, of course, explicit instructions from a school).

5. If you are a native speaker, don’t take the language test! College admissions officers aren’t dumb. No one is impressed by a native speaker of Spanish knocking it out of the park on the Spanish Subject Test.

What Matters: The Percentile or the Score?

This is a tough question to answer, actually. Let’s consider how this works using my favorite test: the Math Level 2.

As of the most recent released statistics, a perfect score on the Math Level 2 is only the 83rd percentile. This has, over the years, led to any number of freak-outs and, frankly, a lot of bad advice. I’ve heard tutors who I very much respect claim “this means if you can’t break [insert number greater than 750 here], you shouldn’t take the Math Level 2!"

As my grandfather would have said: piffle.

Why is a “perfect score" only the 83rd percentile? You have to think about who is taking this test: people applying to the absolute top engineering schools in the country. Top math students applying to highly competitive schools. If a lot of these students weren’t strong enough at math to garner a perfect score, something would be wrong. SAT subject tests are, quite simply, curved differently. For the most part, just worry about getting scores that are roughly numerically equivalent to your SAT scores (or, if you took the ACT, to the average SAT scores for your school).

Summing Up

Find out what the schools you’re applying to require in terms of SAT Subject Tests, schedule them when you’ll be most ready to take them (usually at the end of the relevant academic year), and take the tests the will present the best picture to the admissions committee.