Monthly Archives: April 2010

GMAT percentile rankings, part II

As a private GMAT tutor, I regularly receive calls from students (or potential students) who are nervous about some sort of “imbalance” between their verbal and quant scores on the GMAT.  In many cases, those worries are absolutely reasonable–if you have, say, a 51Q/30V, you clearly have an issue.

In many cases, however, the imbalance might not be quite as bad as it seems, especially if you’re (overly) focused on percentile rankings.  Over the years, I’ve met quite a few people with wonderful GMAT scores (48Q/48V, 44Q/42V, 44Q/49V) who worried that they have an imbalance because their quant percentile rankings are much, much lower than their verbal percentile score.  In many of these cases, I don’t think that the test-taker has much to worry about.

In a previous post about percentile rankings, I mentioned that a large percentage of GMAT test-takers do extremely well (raw score of 47 and above) on the quantitative section, but not so well on the verbal.  I admiringly call this the “Asian effect,” since I’m convinced that the bulk of these GMAT quant studs come from math-intensive education systems.  (The United States, of course, is one of the world’s worst wealthy nations when it comes to teaching K-12 mathematics.  You should never hire an American GMAT tutor… crap, wait a minute… scratch that last part.)

Anyway, I clumsily punched some GMAT data into an excel spreadsheet, and made a little chart out of it.  The chart shows the rough shape of the GMAT verbal score distribution (approximately normal or bell-curved), the composite GMAT score distribution (also approximately normal or bell-curved), and the GMAT math score distribution (not so normal).

Please keep the following disclaimers in mind:

Disclaimer #1:  This data is extrapolated from a GMAT score report.  It is definitely NOT very precise data.  I also tinkered with a few numbers to smooth out the curves, so take all of this with a grain of salt.

Disclaimer #2:  GMAT section scores and GMAT composite scores don’t really belong on the same axis, since you can’t easily convert from raw scores (0-60 scale) to a composite scale (200-800) unless you know the GMAT algorithm… and even then, they still wouldn’t really belong on the same axis.  Again, this is just a rough visual representation.

Okay, enough prefaces–I think you’ll get my point as soon as you see the graph.  Here it is.  Enjoy.

GMAT Guessing Strategy

Conventional wisdom says that you should always finish every question on the GMAT, and that the computer will thrash you silly if you don’t. It even says so on page 17 the 12th edition of the GMAT Official Guide:

F[act] — There is a severe penalty for not completing the GMAT test.

If you are stumped by a question, give it your best guess and move on…. If you don’t finish the test, your score will be reduced greatly.

Thanks to this particular part of the GMAT Official Guide, a lot of GMAT students seem to think that they’ll face imminent GMAT doom if they don’t finish every single question. As a GMAT tutor, I often field anguished calls from students, who swear that their scores would have been much higher if they hadn’t accidentally ran out of time before they had a chance to answer question #37 on the quant section.

And guess what? A random guess on question #37 doesn’t seem to matter all that much. This little fact comes straight from the (tragically underused) official GMAT blog, which rarely receives more than one new post per month.

I strongly encourage you to read the GMAT blog post, or you could go straight to the pdf of the entire study if you’re feeling ambitious. And if you’re not feeling all that ambitious, here are the highlights:

  • the last question or two never really matters much — so don’t freak out if you don’t have time to guess
  • if you have five or fewer questions left on the verbal, it doesn’t really matter if you omit questions at the end
  • if you are of below-average ability on quant, it might actually be better to omit questions at the end
  • if you are of relatively high ability on quant, you are better off guessing on the last few questions… but again, it doesn’t make a big difference if you omit just one or two questions at the end

Pretty crazy stuff, right?  All of this information apparently comes from actual GMAT test data, and it definitely represents a departure from standard GMAT test-prep advice.

The bottom line is that a few random guesses or a few “skipped” questions at the end of the test won’t ruin your GMAT score, one way or the other. Remember that you have a huge margin for error on the GMAT, and you can miss a crapload of questions and still get an absolutely wonderful score on the test.

So relax a little bit. Whatever you do, don’t stress if you can’t answer the last quant question—it certainly isn’t worth causing the sort of anxiety that may inspire unnecessary verbal underperformance or a tearful call to your GMAT tutor.