Let’s face it—a lot of the GMAT materials out there are pretty rubbish.
In fact, at least once a month, I get offers from some dodgy company or another offering me 1/3 to 1/5 my hourly rate to write something like ten questions per hour.
(Generating fully new, good quality questions takes more like one hour per question, if you were wondering).
All I can assume is that the people who end up writing most third-party (non-Official) materials are lured into doing so through guilt, child support, or a heaving meth addiction.
Or maybe they got sick of their jobs overseeing the deep-fry basin at Burger King and are looking for a lower-paying gig on their way to the gutter.
Needless to say, I don’t take these jobs.
For that matter, I almost invariably encourage my students to use as many Official Materials as possible.
This is even to the point of outlining all of the questions that are replaced every time an Official Guide is released and compiling the old ones so that we know which are fresh.
Call me nerdy.
Still, even the best non-Official GMAT questions might test relevant concepts, but they tend to be written in an entirely different voice and tend to have an remarkably different internal structure than Official questions.
HOWEVER, a recent discussion has spurred me into thinking about something.
It’s obvious to anyone who’s studied GMAT to a high standard that we can’t always rely on Official Materials, for no other reason than that there aren’t enough difficult questions.
There’s really no way to get enough Official Questions to consistently see enough 700-level questions in a row to approximate an actual GMAT situation.
Thus we have to collect killer questions anywhere possible.
The main source, for Quant, is Manhattan’s venerable Advanced GMAT Quant. Now, of course, this book isn’t going to help much in the voice of the questions.
But the wrong voice isn’t necessarily a bad thing.
If I can go through the Manhattan materials, for example, or other decent materials such as the Jeff Sackmann books, and understand the point, then what makes me different from other people?
I seem to be able to get use out of these materials, so how does one extract the useful information?
Actually, it seems to me that the useful experience here comes not from the writing of the question—if anything, the Official questions will be clearer and therefore easier—but being able to extract the idea of the question even from a situation where the writer of the question is not able to express herself clearly enough.
This teaches two things:
First, the ability to extract information from difficult presentation.
Now, the GMAT presents information in an intentionally confusing way, and many of these questions are actually unintentionally confusing, but is that necessarily a bad thing?
Second, the ability to adapt to new situations.
After all, you are looking at information presented in different formats all the time. The concepts might be the same, but you’ll have to dig it out of new presentations.
Even if the presentation is sloppier or somehow different, that doesn’t necessarily make it bad.
Put it this way: Eric Clapton might sound better–from a technical standpoint–than the Rolling Stones, but one is 100% pure Dad Music and the other is still relevant (Some Girls and before, obviously).
You don’t need to have everything presented perfectly in order for it to be useful.
What’s the point here?
Not everything is perfect. The more you can adapt to using imperfect materials, the more you can adapt to the differences between practice questions and the invariably different questions you will see on the test.
Quality non-Official practice questions are often approximately 10-15% different from whatever Official question they used as a base, with most of that difference being from different voice, phrasing, etc. in the language.
An Official question that you haven’t seen before is 20-30% different from other Official practice questions you have seen—otherwise, it wouldn’t be a new question!
If anything, using the non-Official questions have as much merit as the Official questions.
Practice as much as you can with decent materials. Don’t stand for huge errors, and if you find too many of them, quit using that book.
A little bit of difference in voice isn’t necessarily a bad thing, especially with really tricky concept-based questions.
Still, use Official materials as much as possible in the 2-3 weeks before the exam, just to get used to the voice.
You want to go in feeling as comfortable as possible with how the questions are actually presented.
As for other questions, avoid throwing out the baby with the bathwater.
Some non-Official resources that are worth your time:
Chuck Dreyer is a colleague of mine in London and provides thoughtful, effective explanations for some of the nastiest Official Guide questions out there!
Very useful companions to your OG set.
The perennial “Manhattan Advanced.” You don’t even have to say the rest of the title.
These are nice and tricky questions — GMAT Math and GMAT Verbal are both here — just click right or left!
and finally, perhaps the best “bang for the buck” even for non-Official Materials, the Magoosh questions and videos.
It’s a lot of material and the explanations are great. Well worth your perusal!
Finally, don’t think I’d forget to sell my own stuff:)
Here is my Sentence Correction Guide, Last Minute GMAT Grammar:
and its audiobook version: