GMAT Percentiles If you’re applying to a top MBA program, you’ve probably read that you…
If you even scratch the surface of a GMAT prep book, a GMAT forum, or just a random GMAT conversation on the street (those do happen, I swear), you’ll hear something about the scoring algorithm — that you MUST get the first 10 questions right, that you’re doing poorly if you get an easy question in the middle of the test, and so on (both of those “facts” are actually myths, by the way). People tend to react to uncertainty in counterproductive ways, and a seemingly inscrutable algorithm spitting out Quant questions from a pool of thousands of questions certainly welcomes uncertainty. Over the years, I’ve seen students react to this uncertainty in different ways. Some start panicking from the first question and never give themselves a chance to really work through a problem. Some guess on a question at the first sign of trouble. And most end up attempting every question until they look up at the clock and realize that they have to guess on the last 5 or 6 questions.
All of these are problematic and sub-optimal approaches, and, to a large extent, they derive from confusion about the scoring algorithm. I’ve said it once, and I’ll say it again: The algorithm is designed for you to miss questions! I know it’s counterintuitive, especially when our educational system defines success on a test as getting 80%+ of the questions correct. But, for the purposes of the GMAT, an 80% accuracy rate on the Quant is exceedingly rare. As I’ve discussed elsewhere, the truth is that you can get a very high Quant score and still miss almost half the questions. This fact should, in of itself, be good news, but, more importantly, it should dictate the approach you take toward budgeting your time on the exam.
Think of it this way: If the algorithm is designed for you to miss questions, then missing questions that are out of your scoring range won’t prevent you from getting the score you’re aiming for. Let’s say you’re shooting for a 75th-percentile Quant score, and you miss a question tagged at 80th-percentile difficulty. Missing this question won’t hurt your chances of achieving your desired score; it’ll only impact your chances of scoring at or above the 80th-percentile. So how should this impact your timing strategy? Given the time pressure that basically everyone feels on Quant, it would be ideal to just guess on all the questions that are above your range and leave that precious time for questions that you need to get right for your desired score. Of course, the issue is that you don’t know which questions are tagged at which level of difficulty. Instead, you should focus on developing strategies for identifying situations in which your likelihood of answering a question is low. A good example would be any time you get a question that touches on one of your weaknesses. For most test-takers, questions dealing with combinatorics or rates would fall into this category. But such a strategy won’t be sufficient. Inevitably, you’ll see questions on topics you’re comfortable with, but that still give you trouble. In these situations, you might be tempted to simply start doing something and hoping that it’ll “click.” I’ve seen students adopt this strategy over and over, and, unfortunately, it’s probably the least effective approach you can take toward a question. Your first step in answering any GMAT quant question is determining how you’re going to tackle it. If you decide to just dive into a question without such a plan, you’re going to suffer from two distinct disadvantages: 1) You’ll end up wasting precious time on steps that might not be necessary and 2) You’ll end up wasting precious time on a question that you’re probably going to miss anyway. A general rule of thumb should be the following: If you’ve read a question twice and still don’t have a concrete plan of attack, you’re better off guessing than trying to stumble upon the answer. If a question is difficult to decipher after two reads, it’s probably a very difficult question, and, more importantly, it’s probably a question that will take you 3 – 4 minutes to answer. And this doesn’t even mean you’ll answer it correctly! The worst use of your time is to spend 3+ minutes on a question AND miss that question. Such an approach will force you to scramble on questions in your range, and, ultimately, you’ll end up missing questions that you could’ve answered correctly had you simply budgeted your time properly.
Of course, all of this is easier said than done. It takes some adjustment to understand the scoring algorithm and to tweak your approach appropriately. This is why it’s important to take sufficient practice tests before your exam, and this is why, even when you’ve addressed all the content on the exam, you still need to develop the appropriate approach to optimize your GMAT score.