Category Archives: GMAT

GMAT anecdotes, advice, and content.

my quest for 800… er, 790

Posted on July 8, 2009 | 1 Comment

I was just thinking about my previous entry about how hard it is to score an 800 on the GMAT, and realized that I was arguably being a little bit too impersonal about it. For what it’s worth, I’m definitely gunning for an 800 next time I take the test. Is that a realistic goal? Probably not–I’m a precise test-taker, but I’m not sure that I’m quite precise enough to get an 800 on the GMAT. But I’d be lying if I said that I wasn’t going to try.

(Though I might screw myself over in a small way if I manage to get an 800. Test-takers who earn an 800 are banned from taking the GMAT for five years, which means that I’d miss out on my annual visits to the testing room. Boy, that would suck.)

And just to recap, my GMAT tutoring career began with a subpar practice test when I worked for a large test-prep company, and I slowly have worked my way through the 700s. My most recent score was a 780 (51Q/47V). If there’s room for me to improve, it’s probably in the verbal section. I would love to crack 51 in math, but I’ve been humbled enough times already, and I don’t think that I’m the guy who can pull that off.

So what would a GMAT tutor do to improve on his own verbal score of 47? The same things, basically, that I ask my students to do once they’ve ripped through all of the official guides. Lots and lots of LSAT practice to build skills and stamina for the hardest critical reasoning and reading comprehension questions, and then some polishing of my grammar and usage, based largely on (fun!) resources such as style guides and grammar manuals. It never hurts to go back through official SC questions with a fine-toothed comb, but I think we all agree that the hardest stuff in the official guides and GMATPrep tests do not even begin to prepare you for the real thing… especially not if you’re shooting for an insanely high GMAT score.

My schedule is still funky as I adjust to my new lifestyle in NYC, so I don’t know when I’ll have the time to re-take the test. Last year, I took it on about 24 hours’ notice, and I’ll probably do something similar this time around–when the mood strikes (and my schedule allows), I’ll jump on the first GMAT appointment I can find. As soon as I do that, I’ll post a few entries and share my experiences.

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Brutal SCs

Posted on July 5, 2009 | Leave a comment

One of my favorite new GMAT students in NYC asked me to take a look at a set of questions that have been floating around the internet for awhile.  It’s called Brutal SCs, and contains 70 sentence correction questions.  They’re supposed to be brutal, I guess.  And they are… just not in the way that the author (or compiler?) apparently intended.

I’d be lying if I told you that I analyzed every single question in the document with extreme care, but I did take a reasonably thorough survey of the first 25 questions.  I found major typos in four questions, and a fifth question had a misuse of the phrase “due to” in the non-underlined portion of the original sentence.  These mistakes may or may not have impacted the answer, but they definitely made me question the quality of the resource.

More importantly, several of the answers seemed to be just plain wrong.  At least two questions (#21 and #22, if you happen to have a copy) are very clearly flawed, and I’m deeply suspicious of several others.  In short, at least 20% of the questions in this resource contain mistakes of some sort, and I suspect that this figure is an understatement.

The bottom line:  stay away from Brutal SCs, and find another way to practice your GMAT sentence correction skills.

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how hard is 800?

Posted on July 3, 2009 | Leave a comment

Before I started to tutor in NYC, one of my old students asked me how long she would have to study to get an 800 on the GMAT.  I told her that she would be crazy to even think about trying.

I meant her no disrespect at all.  She is about to start her MBA program at the University of Chicago, so it’s safe to say that she’s an extremely talented woman.  But achieving an 800 on the GMAT is ridiculously tough.

Let’s start with some stats from the official GMAT site:  fewer than 50 students (out of roughly 250,000) score an 800 each year.  If you’re keeping score at home, this means than an 800 score would fall somewhere above the 99.98th percentile.  And that’s assuming that there are close to 50 people who get a perfect score–the figure could, in reality, be much smaller.

Now, let’s talk about the torture that GMAT will put you through if you start to get close to a score of 800.  (For the sake of illustration, I’m going to talk mostly about the quantitative section here.  The same ideas apply to verbal, but are trickier to explain.)  On the GMAT math section, formulas are of limited value on difficult questions.  You obviously need to know all of the fundamentals, but it’s easy enough for GMAT writers to cook up an evil question that defies formulaic thinking.

At the highest levels, there are some extremely wicked questions.  Last time I took the test, I ran into an absolutely brutal series notation question that destroyed me.  I spent eight minutes on it, and I still had no idea how to solve the stupid thing.  It was so complex that I couldn’t even remember the question after the test.  And believe me, I was trying like crazy to wrap my head around it, so that I could study it later. Nope.

So basically, the GMAT writers are brilliant enough to lay waste to almost everybody (including arrogant, Stanford-educated GMAT tutors with nearly 10 years of experience), at least some of the time.  I might have gotten 35 questions correct on the quant section last time around (though I’m sure that I made some dumb mistakes somewhere… I can say that I was extremely confident in 35 of my answers, and definitely missed at least two questions), and I scored a 51.  But the test can still stump me whenever it wants to, apparently.

And let’s talk about that raw quantitative score of 51.  I’ve never heard of anybody getting higher than a 51, and I’ve been stuck on that score for a long time.  Strangely, it’s theoretically possible to get a raw score of 60. (Visit http://www.mba.com/mba/thegmat/gmatscoresandscorereports if you don’t believe me.)  But I’m pretty sure that I understand what it means to get something higher than a 51:  you need to get those evil questions right, somehow.  I suspect that the impossibly hard questions would have kept coming last year, even if I’d managed to get that series notation beast right.

I’ll go back in to take the test again in the next few months, but the odds that I’ll ever get to 800 remain slim.  There’s absolutely no room for silly errors, and I would have to somehow slug my way through the dirtiest of the questions.  You won’t, of course, find any truly brual, 800-level questions in any official GMAT material, including the GMATPrep and GMAT Focus tests.  So there’s no way to practice, really, once you’re beyond a certain level.

I’m sure that very few of you are really gunning for an 800 (it won’t, in all honesty, really help you get into an MBA program), but I find it fascinating that the writers of the GMAT make it so tough to get the top score.

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nobody reads your essays, part II

Posted on July 2, 2009 | 1 Comment

Most GMAT students I’ve run across really don’t worry all that much about the analytical writing portion of the test, but I occasionally meet somebody who is absolutely neurotic about this part of the GMAT. In my opinion, there’s rarely any need to spend more than a token amount of time on AWA.

First of all, one of the main reasons why MBA programs care about the GMAT is because of rankings. Unfortunately, US News & World Reports will look less favorably on a b-school if the program has low composite scores, so admissions committees are forced to focus on your GMAT score. (The test is somewhat valuable in other ways, but that’s a story for another day.)

Of course, AWA has absolutely nothing to do with your composite score, and it therefore has no impact on MBA rankings. You don’t want to completely screw it up, but there’s no reason to believe that your AWA score of 5.0 would keep you out of Stanford. The adcom might start to wonder if your AWA score is, say, 2.5, but I see no reason to worry if your score is reasonably high. They’re looking for business leaders with decent communication skills, not novelists.

So what does it take to earn a “reasonably high” score? Not much, really. I’ve seen some really, really bad writers earn scores of 5.0 or 5.5. They took advantage of the fact that nobody really reads your AWA essay.

As you probably know, GMAT essays are graded by a computer and by a human; if there’s a discrepancy between the two scores, then an additional human reads the essay. Obviously, nobody really knows exactly how the computer’s scoring system works, but I’m absolutely convinced that the program primarily looks for structure using basic keyword algorithms. From there, it probably counts things like the average number of words per sentence, the average number of letters per work, and then it checks for grammar, usage, variety of words used, and perhaps spelling. I suspect very strongly that the structure is the most important part of the scoring system; spelling might not even count at all. (Again, I’ve seen some horrid spellers get really good scores.)

The “human,” for his part, is ultimately looking for the same things as the computer: structure, clarity, correctness, richness of language, etc. But this human probably doesn’t actually read your GMAT essays any more closely than the computer. Again, imagine that you’re the poor slob who gets paid $20/hour (as of a year or two ago, GRE and TOEFL graders earned $20/hour; I don’t know whether the rate is similar for GMAT) to read bazillions of these essays, most of which are tragically bereft of interesting content. Are you going to read every single word? Hell, no. You’ll skim the introduction, maybe read the first sentence of each paragraph, and then maybe skim the conclusion. (And if anybody asks, you’ll tell her that you read every single word with great care.)

When I wrote about the people who read (or skim) your MBA essays, I claimed that you should strive to make your essay interesting–you want them to read it carefully, right? For the AWA, you don’t necessarily care if the human grader (or the computer) actually reads your essay. You just want a good score.

So focus on structure, even if that means that you produce an essay that would, under normal circumstances, seem like a crappy, contrived piece of writing. Don’t beat around the bush: every paragraph should start by clearly stating the main point of the paragraph. The entire essay should start with a crystal-clear thesis statement. Somebody should be able to read the first sentences of each paragraph, and still basically understand the entire essay. Just make sure that you leave a few minutes to proofread the essay, just to make sure that you haven’t committed egregious grammar, usage, and spelling errors. (If this means that you don’t write a terribly long essay, that’s fine–quality matters more than quantity.)

Honestly, it’s almost that simple. If you lay out your argument in a completely clear, 5-paragraph format, you’ll be in good shape, especially if your writing mechanics (grammar, usage, etc.) are basically solid. You might ultimately write an essay that is about as much fun to read as a phone book… but fun isn’t really the point, is it?

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why you shouldn’t worry (too much) about percentile rankings

Posted on June 28, 2009 | 1 Comment

I’ve already met some brilliant MBA candidates in my first few weeks here in New York, but the most gifted GMAT student I ever tutored was probably a young woman I met in DC, before my Manhattan days.  She was a cum laude graduate of Duke University’s economics program, and she had already earned a ridiculously high score on the GRE.  She was solidly scoring in the 700s on her GMAT practice tests, and just wanted help getting her math score “as close to perfect as possible.”

I’ll be honest:  there’s a pretty good chance that this particular student (let’s call her Susan) was smarter than I am, and that’s a beautiful and intimidating situation to be in as a GMAT tutor.  I suspected (correctly) from the start that she didn’t have any fundamental GMAT math weaknesses; all I could offer was some practice questions designed to help her make connections on the hardest GMAT math questions.  (Basically, math formulas are of limited value on hard GMAT questions, and you need to be able to “see” a connection before you’ll have any prayer of getting the right answer.  I’ll expand on this in another post.)

Basically, tutoring Susan meant spending two hours inventing the hardest GMAT-style questions I could possibly come up with.  I loved it, and I probably learned more from the experience than she did.  Occasionally, I’d manage to stump her, and that was great.  After about eight or ten tutoring sessions, we decided that she had probably “worked her GMAT math muscles” as much as was reasonable, and she went to take the test.

And she was bitterly disappointed when she looked at her percentile ranking.  She scored in the 99th percentile on the verbal, and her composite score was also in the 99th percentile.  Her quantitative score, however, was only in the 84th percentile.  How could this be true?  She scored a 760, but somehow wasn’t even in the top 10% in math? WTF?

If you have any experience with the GMAT, you surely realize that a score of 48 on the math is pretty darned impressive.  (Frankly, anything above 40 is probably good enough to allay any fears that an MBA admissions committee might have about your quant skills, but that’s another topic entirely.)  For whatever reason, however, there are lots of impressive math whizzes taking the GMAT.  A full 20% of test-takers earn a score between 47 and 51.  The score distribution, then, is not a bell curve at all for the quantitative section–it basically looks like a slowly increasing function, with an extra little jump at the end.

I admiringly call this the “Asian effect.”  Based on anecdotal evidence, I’m convinced that most of the people who achieve quantitative scores in this range are not products of the United States education system.  (News flash:  by global standards, we Americans are generally pretty lousy at math.)  Basically, there are a ton of people in Asia who demolish the quantitative section of the test, and make a whole lot of GMAT-takers feel inadequate when they see their percentile score.

Interesting, the verbal score distribution is almost a perfect bell curve.  Similarly, the composite score distribution is also a fairly non-skewed bell curve.  This suggests that most of the GMAT “quant ninjas” are not particularly great at verbal.

The bottom line?  If you’re trying to get into top MBA programs, it’s probably OK to have a math score “only” in, say, the 70th or 75th percentile.  Don’t let the percentile score mess with you:  if your raw quant score is comfortably in the 40s, it probably won’t, by itself, sabotage your MBA dreams.

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ignore the man behind the GMAT curtain

Posted on June 14, 2009 | Leave a comment

Pretty much all of my students have, at some point or another, seen a really easy question on the GMAT, and had a mild panic attack as a result.  We all know that the test is adaptive; if, say, question #25 seems really easy, doesn’t that mean that the test-taker is doing really really badly?

No, of course not.

Well, okay… maybe.  If you’re doing really badly, you probably will see some really easy questions, particularly on the math section of the test.  But there are other possible explanations, and perhaps you’ve heard them before; based on my experience as a GMAT tutor, these explanations still don’t prevent students from freaking out a little bit.

First of all, there are plenty of experimental questions on the GMAT test.  You might be kicking some serious butt, and then a complete softball comes your way.  Is it a sign that you weren’t really kicking butt?  Probably not.  You might just have received a little unscored nugget.  Answer the question as if it counts, and then put it out of your head.

I’m also convinced that the GMAT algorithms group questions by topic, and the test actually accounts for your performance on each topic.  You might have done wonderfully on the first, say, 12 questions on the GMAT, but then you miss your first geometry question.  Perhaps the test recalls that you screwed up on geometry, and then gives you an easy geometry question next time.  This is just speculation on my part, but I think it’s possible that seemingly easy questions might come at you when you’ve displayed weakness on a particular topic–even if you haven’t, in general, shown yourself to be a weak test-taker.

Most importantly, you should never worry about the difficulty level of the questions.  If a GMAT question seems easy, read it really, really carefully–it might not be as easy as you think, or you might be missing something crucial in the question.  And even if it is easy, why the hell would you want to waste your energy worrying about it?  Get the question right, and worry about your score at the end.

This might seem obvious to you, and this post is obviously just a little bit of nagging.  But it’s funny how many people apparently need to be reminded that they shouldn’t waste their time thinking about the algorithm and their score during the GMAT.

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stealth exponents

Posted on June 11, 2009 | Leave a comment

It’s always a little bit tricky and annoying to write math problems on a GMAT blog (there’s no way to comfortably write equations, unless you want to import images), but I’ll do my best with this topic.  I just want to make a few little comments about exponents, and how the GMAT Official Guides (referred to hereafter as “OGs”) can lull a perfectly good GMAT student into complacency on the topic.

Hopefully, you know all of the basic exponent rules.  If you’re multiplying two terms with the same base, you’ll add the exponents (example:  x^3*x^4 = x^7).  If you’re dividing, you know that you subtract the exponents, and then you might encounter something like a “power of a power” question (example:  (x^6)^2 = x^12).  If you know these rules and a few other basics (i.e. what happens if an exponent is negative, a fraction, or zero), you’ll be fine on the GMAT.  Right?

If you’re focused on the OGs… well, yes, you’ll be fine.  Let’s take a quick survey of the exponent questions in the problem solving section of the 12th edition of the OG:  #15, #28, #46, and #108 all contain exponents, but they’re mostly a matter of calculating (or simplifying) some numbers.  #104 and #110 look like exponent problems, but both are really about factors, not exponent properties.  #137 could be solved using exponent properties, but is just as easily done with some simple calculations and logic…

I could go on.  My point is, most of what you encounter in the OGs doesn’t require much knowledge of exponent properties.  And when you do need to use exponent properties, they’re just covering the basics.

Funny, I didn’t see anything basic last time I took the GMAT, and neither did most of my students who scored above 600.  I keep hearing the same refrain:  the exponent problems looked nothing like they do in the OGs.

I’m convinced–based on the GMATPrep, GMAT Focus, and the real thing–that the GMAT is much more likely to show you an exponent question that has something to do with factoring and/or “base conversion.”  Neither of these topics are dealt with much in any prep book, at least not to my knowledge.

Please accept my profuse apologies for the crappy notation, but here are a couple of examples of realistic, harder exponent problems (NOT from official GMAT material, lest I incur the wrath of some bigshot NYC lawyer sent by the bigshots who write the GMAT):

(7^10 – 7^8)/3 = (2^x)(7^y).  If x and y are integers, then what is the value of x + y?

3^(x-1) – 3^(x+1) = -(9^5)(2^3).  What is the value of x?

I’m not going to post solutions until I’m begged repeatedly, but hopefully you see where I’m going with this.  You’re going to see problems that require some factoring, as well as the ability to make some ostensibly unlikely connections.  Unless you’ve seen these problems, you might be wondering where the heck the 2′s are coming from.

Welcome to the GMAT.  If you’re not uncomfortable, you’re probably not doing well.  Either that, or you’re way smarter than I am, and you shouldn’t be wasting your time reading a blog posting about exponents on the GMAT.

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why I love the GMAT

Posted on June 5, 2009 | Leave a comment

When I first encountered the GMAT, I was working at a major test-prep firm as a GRE and SAT instructor.  At the time, I was 23 years old, and had absolutely no thoughts of business school.  For that matter, I hadn’t even finished my undergraduate degree; I was dancing professionally during an indefinite hiatus from university, and there was no reason why I would have any interest in the GMAT.

But as luck would have it, my company needed a GMAT teacher, and I was ushered into a computer lab to take a practice test.  After clobbering the ACT, SAT, and GRE, I figured that the GMAT would be basically the same deal.  For the first time in my life, I did “just okay” on the practice GMAT.  I did well enough to be initiated as a GMAT instructor, but I was nowhere near a perfect score.

And my curiosity was piqued.

Fast-forward eight or nine years, and I’m still playing with the GMAT.  I’ve worked as a private tutor for a long time now, and I’ve spent quite a bit of time tutoring the SAT and GRE and ACT–but there’s a special place in my heart (or brain?) for the GMAT.

The GMAT is, without question, the most complex and nuanced standardized test out there.  There’s absolutely no way to boil the GMAT down to a nice, simple series of tricks.  The GRE, by contrast, employs an extremely limited set of questions; once you know what to expect on the test (particularly the quantitative section), it’s just a matter of execution.  The GMAT seems almost infinite, and they seem to write questions that only the most ridiculous of geniuses are able to solve.  (When I took the GMAT last year, I spent eight minutes on a single question… and still had absolutely no idea how to solve it.  Whoever writes these questions is a bad, bad dude.)

So that’s why I’m here, all these years later.  Still playing with GMAT, still trying to figure out every little nuance and evil question, so that I can offer the most help possible for my friends and students who want to achieve their MBA goals.

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beware the knockoffs, part I

Posted on May 28, 2009 | 2 Comments

I was reading a thread on a GMAT forum a few days ago, and saw that the owner of a test-prep firm was telling students that they should avoid independent GMAT tutors who rely on commercially available GMAT materials.  The owner’s logic sounded good (hey, look, we know enough about the test to write our own book!  hire us!), but I wholeheartedly disagree with the idea that you should use material written by random companies.  The only GMAT materials you should completely rely on are the official guides–which are, of course, commercially available.  Anybody who claims that they’ve written something better is either lying, or completely deluded about the complexity of the GMAT.

It is extraordinarily difficult to copy the writing style of the GMAT, even on math questions that contain few, if any, words.  The GMAT is a ridiculously complex test, which is exactly why I love it.  (And, perhaps, exactly why you hate it.)  I don’t know exactly how many brilliant test-writers are employed by GMAC, but I suspect that it’s a fairly large fleet of people, and I’m certain that questions are very thoroughly vetted before they are ever inserted into the scoring algorithm for the real test.

The challenge for “knockoff” GMAT writers is even greater on the verbal section.  I’ve written and edited TOEFL practice tests, and I can say that took an enormous amount of effort to make our material sound even vaguely like the real thing.  GMAT verbal questions are even more detailed than TOEFL questions, and it’s extraordinarily hard to write GMAT questions that will be “hard in the same ways” as the real thing.  I’ve found countless mistakes in widely-published GMAT verbal material, and the companies seem to struggle with all three verbal question types.  Frankly, most of the mass-market publications will do more harm than good if you’re using them as primary verbal prep resources.

A majority of my students contact me after they’ve already taken either a prep course, or a reasonably thorough self-study course.  I’ve seen refugees from Veritas, Manhattan, and Kaplan in roughly equal numbers, as well as an occasional graduate of Princeton Review or other (less well-known) competitors.  Some of these companies are better than others (and one, in my opinion, stands head and shoulders above the rest), but the bottom line is that all of them are inevitably limited in their ability to replicate the GMAT experience.

For what it’s worth, the company that makes the very best “knockoff” materials manages to capture about 80-90% of the real GMAT experience, and that’s an astounding achievement.  (I feel that it would be inappropriate to make an endorsement here, so I won’t name the company.)  This same company probably makes its verbal questions look like the actual GMAT only 70% of the time–it’s amazing how often I see (or hear of) real GMAT questions that fall outside the scope of even the best “knockoff” curriculum.  Again, I think that this company is absolutely amazing for doing as well as they do, but that shows how hard the task of “reproducing” the GMAT really is.

The other companies?  Not even close, and I’ve looked at material from some of the most expensive, “boutique” test-prep firms, as well as the household names.  As a general rule, the verbal questions will do more harm than good, and even the second-best large company produces tests that are riddled with typos and errors.

I mean none of this disrespectfully–quite the opposite, actually.  These firms throw a ton of resources into an extremely difficult task, and their results are necessarily mixed.  But before you buy a practice resource sold by a small company, be very aware that the material will probably be filled with inaccuracies.  There are presumably a few gems out there, but all of them should be handled with extreme care.

I’m regularly asked if I include some sort of textbook or workbook or self-published GMAT guide as the backbone of my tutoring program.  I write supplementary GMAT questions all the time, but trust me on this:  you probably wouldn’t want to hire me if I relied primarily on a self-published resource.  A good GMAT tutor or test-prep firm will supplement lessons with their own materials, but any independent operator who says that they’ve written a magical, best-in-the-industry GMAT resource is probably exaggerating, if not egregiously lying.

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