It never ceases to amaze me how few people use the official GMAT resources that are available. This is perhaps a credit to how good the major test prep companies have gotten at convincing people that their resources are an accurate representation of what is on the test. While third party resources can be very valuable for learning the content that appears on the GMAT or for learning how to more effectively approach questions, when it comes to doing practice questions or especially practice tests, there just is no substitute for using official GMAC-released practice questions and practice tests.
I have written about this in other blog posts, but I am not exaggerating when I say that probably 1 out of every 2 people who contact me for help with the GMAT has either never taken an official GMAT practice test or has not been using official GMAT questions to practice with (and these are people who HAVE been using other resources like those of ManhattanGMAT or Kaplan or one of the other test prep companies). I think what usually surprises me most in these encounters is that people don’t even seem to understand the difference! Often the reaction that I get is something to this effect: “You mean that ManhattanGMAT tests are not official tests?!”
Sometimes just getting people to start using official GMAC resources is enough to get them a significant score increase. In fact, sometimes just even having them take an official practice test is enough. Again a very common occurrence for me is a student who contacts me complaining that they have studied a lot but are still stuck at the 550 mark or 580 mark or something like that. When it becomes clear that all they have done is ManhattanGMAT tests I will often say, “well how do you know you are stuck at a 550 mark when you have never done an official test?” In many of these cases the person then goes and takes an official GMATPrep test and contacts me back to let me know that they scored in the mid-600’s or some score that was significantly higher than what they had been scoring on the ManhattanGMAT or Kaplan tests that they were taking.
Again I am not arguing that third party resources are useless. Even the practice tests can be useful when used for the correct purpose. But trying to give yourself an authentic test-taking experience or trying to gauge exactly what score you are at are not reasons to take a third party test!!! Test prep company materials are particularly good at teaching the content that serves as the foundation on the Quant and Verbal sections of the test and some resources are also good at providing insight into how to approach the questions more effectively. The official GMAC resources are not particularly good in those regards.
But once you have learned the core fundamentals and have begun to understand how to approach the questions you MUST, MUST move on to official questions and then official practice tests to ensure that you are practicing on the types of questions that will appear on the exam.
There are a couple of reasons this is so important. First of all, it is very difficult to write questions that really accurately reflect the questions on the actual exam and test prep companies typically do not have their absolute most experienced and knowledgeable people writing the questions. This is especially true for Verbal questions, which are so hard to write in a way that accurately reflects the logic of the questions on the actual test. If you write a sentence correction question that is too grammar focused and not logic and meaning focused enough then you have a question that really departs from the actual questions in a pretty significant way.
Another issue is the distribution of questions that you see. Often test prep companies focus too much on some question types and not enough on others. So you might be practicing on a lot of combinatorics and probability questions when these questions are not that well represented on the actual test (and even when they are, they are often very difficult questions that may be better to guess on anyway). This is especially true of 3rd party practice tests – if the distribution of different question types is not accurate to the test then the practice test is not a realistic representation of the test. What’s worse is that when you analyze your performance on the test you may walk away with the belief that you need to work on particular topics (like combinatorics and probability) when you are coming to that belief only because you saw an unrealistically disproportionate number of those questions.
And with the practice tests, level of difficulty is important too. If the questions on a non-official practice test are just too hard then you may run completely out of time and draw the conclusion that you have serious time management issues that you don’t actually have. And the score that the tests output may lead you to believe that you are doing much better or much worse than you actually are – test prep companies try their best to approximate the scoring algorithm of the actual GMAT, but no one knows exactly how the algorithm works so the scoring system on third party practice tests is bound to be at least a little bit inaccurate (and in some cases it can be wildly inaccurate).
The official guide books and the official GMATPrep tests, on the other hand, present real questions that appeared on previous GMATs (which means that the questions underwent a rigorous vetting process before they ever made it onto the exam). The distribution of questions, both in the books and on the tests, is a good representation of what appears on the actual GMAT. And the scoring algorithm on the GMATPrep tests is the actual scoring algorithm that is used on the GMAT.
So people, please, please use the official GMAT resources!!! Again it is fine and even helpful to use third party resources to help you master the foundational material and learn how to approach the questions more strategically and effectively. But when it comes to practice you MUST use official questions. And when it comes to taking practice tests and gauging your overall performance, you MUST use the official GMATPrep practice tests!