Using (and Misusing) GRE Practice Tests

Among the many myths that abound regarding optimal preparation for the GRE, one of the more common and, unfortunately, more harmful ones is that there exists a direct relationship between quantity of practice tests taken and score improvements. And, unfortunately, this myth is perpetuated by large GRE classes that will advertise 6 or 8 or 15 practice tests in conjunction with their course offerings. All too often, I’ll get a phone call or e-mail from a panicked student who can’t fathom why his/her score hasn’t improved despite having taken 8 practice tests over the past few weeks. Now, it goes without question that practice tests have an indispensable role in your GRE preparation, but unless you take the right practice tests at the right time in your preparation and at the appropriate frequency, you may end up doing more harm than good. So what are some good rules of thumb for GRE practice tests?

1) Take a diagnostic test!

It can be unnerving to dive into a practice GRE when you haven’t done any preparation for the exam and have forgotten how exponents work, but without a proper baseline, it will be difficult, if not impossible, to assess your strengths and weaknesses and develop your study plan accordingly. Even if you feel confident that, for example, Quant is your weakness or Reading Comprehension is a strength, your self-assessment might be skewed in either direction, and there’s no way of knowing this unless you see the results of a diagnostic test. There is, of course, a surfeit of practice tests out there, but, as I’ll discuss below, your diagnostic test should be an official one from the GRE PowerPrep Software.

2) Don’t use practice tests as tools to learn content or strategy.

Many students think that the best way to solidify conceptual or strategic knowledge is to immediately implement that strategy in the context of a timed practice test. On the surface, this might seem logical, since, after all, the purpose of all of your preparation is to apply these skills and knowledge on the real exam. However, from a pedagogical perspective, new skills and knowledge need time to be consolidated in your long-term memory, and the only way to accomplish this in a way that doesn’t compromise what you’ve learned is through consistent, rigorous, and meticulous practice. Just as it would be foolhardy for someone who just learned a new piece of music to immediately play it a recital, so too would it be inefficient to think that the best way to hone newfound content knowledge or strategy is to apply it on a timed practice exam. You have the Official Guides to learn and reinforce content; leave the practice tests to learn how to adjust to the scoring algorithm and to identify any trouble areas after you’ve gone through all the major content. Which brings me to the next point…

3) Use practice tests to develop proper time management and guessing strategies.

In contrast to the linear scoring you may be accustomed to from college or high school, the GRE is a section-adaptive exam on which your overall score is weighted by the level of difficulty of the questions you get right and wrong (in other words, a correct “hard” question is worth more points than a correct easy question, and an incorrect “easy” question is penalized more than an incorrect “hard” question). Because the scoring on the exam is so unorthodox, when many people start taking practice tests, they run into a catastrophic domino-effect. They often overestimate the percentage of questions they need to get correct (especially on the second Quant and second Verbal sections), which means they spend more time than they should on certain questions, which in turn lowers their accuracy on “easier” questions, all of which leads to a score that undershoots their true GRE proficiency. To get past this, you need to take ample practice tests, identify the kind of situations that merit guessing, and learn when to cut your losses on certain questions. This is why it’s so important to take practice tests on a weekly basis for the last 4 – 6 weeks leading up to the real exam. Even if you have all the content knowledge down pat, it will be for naught if you haven’t developed a proper strategy to account for the GRE’s unique scoring algorithm.

4) Save practice tests for the end of your preparation (for the most part)

Okay, so I had to qualify this piece of advice. Here’s the thing: practice tests really serve three functions:

a) Develop a sense of your baseline (point #1)
b) Develop time management and guessing strategies (point #2)
c) Identify any remaining weaknesses as the exam approaches

The functions of points B and C are served only by taking practice exams near the end of your preparation. Generally, I recommend taking one per week for the last four weeks. This will give you enough time to develop a concrete strategy for the algorithm and to address any previously unidentified weaknesses that appear on the exam. The only exception to this is a “mid-preparation” practice test: If you’re going to spend 12 weeks preparing for the GRE, it’s a good idea to take a practice test after week 4 or 5 to gauge your progress in relation to your diagnostic test. But after that, you should wait until you’ve covered all the major content before you start taking practice exams on a regular basis.

5) Use ETS’s official practice tests

Once upon a time, the use of commercial practice exams (i.e. those made by big companies such as Kaplan, Princeton Review, Manhattan Prep, etc.) was inevitable. Until a couple years ago, ETS provided test-takers with only two official practice tests, a woefully low number for anyone serious about the exam. But a few years, ETS released PowerPrep Plus, which provides test-takers with 3 additional official practice tests. Barring extenuating circumstances, five practice tests is sufficient for pretty much any test-taker. Of course, the question stands: why use ETS exams instead of ones made by the big companies?

To understand this point, you need to understand the downside of commercial GRE materials. To summarize: There is NO substitute for official GRE questions. When ETS constructs a question, they will spend upwards of several thousand dollars confirming its validity, eliminating ambiguities, and assessing its level of difficulty. When companies write questions, they’ll often spend less than $50 per question. This discrepancy manifests itself in ambiguities in the questions, disputed answer choices, and a general misconception that correct answers in Verbal are subjective. In reality, there’s always a concrete reason for a correct or incorrect official GRE question, and the only way to get used to this logic and the wording of the questions is to do practice on these official questions.

When it comes to practice tests, this point is only magnified. Not only are official GRE practice tests the only ones that allow you to practice on questions from previously-administered exams, but they’re the only practice tests that use the same scoring algorithm as the real exam. Because the GRE’s scoring algorithm causes so much confusion, practicing on exams made by companies trying to simulate that algorithm might reinforce bad habits and misconceptions about how the scoring works. So stick to the real ETS tests. With five available, you most likely won’t need to look anywhere else.