Just about everyone who studies for the GMAT takes a practice test at some point.  A practice test gives you an idea of what the actual exam will be like, and it approximates how you’ll do on the big day.  However, as many people discover after taking the real thing, practice tests often differ significantly from the GMAT both in the difficulty of the questions asked and the scores predicted.

Much of this difference is due to the nature of computerized adaptive tests, which rely on an algorithm to generate test questions tailored to a test-taker’s ability.  Since the GMAT’s algorithm is a closely guarded secret, adaptive practice tests struggle to reproduce how the GMAT sequences test questions, which accounts for some of the variability between how people score on practice tests and how they score on the actual test.  Additionally, the difficulty of practice test questions does not always match the difficulty of real test questions.

The pros and cons of GMAT practice tests

These differences are a common frustration for those struggling with the GMAT as practice tests can give little indication of what the actual GMAT score will be.  This was the experience of LTG’s founder, Elad.  However, despite these flaws, practice tests can still be put to good use if you understand what these tests do best and what they fail at when it comes to GMAT prep.

What practice exams do well

Though a practice test is not a crystal ball, practice tests:

• Prepare you mentally and physically for the reality of taking the GMAT
• Introduce you to the timing and pace of the test as well as the order of test sections
• Give you an idea of where your score may fall
• Point out your strengths and weaknesses

The first two points are key and where you’ll likely derive the most benefit from taking a practice test.  As it’s been mentioned many times before, the GMAT is a marathon, and it doesn’t make sense to run a marathon without first being comfortable running long distances.  You could say that in addition to verbal, quantitative and reasoning skills, the GMAT also tests your mental stamina and focus through its lengthy duration and how it pairs sections.  Not only do you have to sit and concentrate for up to four hours, but you also have to shift mental gears from writing to doing math problems to reading dense passages of text and then to correcting sentences — all under a time crunch.  Having the mental dexterity to keep your focus takes practice, and practice tests help to build this ability.

The last two points are perhaps what most test-takers expect from a practice test.  Essentially, testers want to know how they’ll do on the real thing and what areas they need to improve in order to get a better score.  Practice tests do provide a general idea of how you may score on the GMAT, but given the previously discussed inaccuracies, it’s best to take this prediction with a grain of salt. Use the test or tests to generate an idea of where you stand and what test areas you are stronger or weaker in, but don’t take their predictions as hard facts.

What practice exams do poorly

As previously discussed, GMAT practice tests can only simulate, and sometimes fairly inaccurately, the experience and result of an actual GMAT exam.  In particular, practice exams cannot:

• Accurately predict scores
• Reproduce the exact experience of the test (i.e. the level of difficulty of questions and the sequence of questions)
• Teach concepts

While the first two points have been well established, the third point is also worth stressing.  Some GMAT students fall into to the trap of placing practice tests at the center of their studying strategy.  The thinking goes that if you master the practice test, then the actual test will be easy.  Acing a practice test, unfortunately, is no guarantee of success on test day, and further, it’s hard, if not impossibly, to actually improve by only focusing on practice exams.

An initial practice test is a great way to establish a baseline of strengths and weaknesses and to build mental endurance, but once you’ve identified what you need to improve, a GMAT practice tests is worthless.  When you take a practice exam, you’re not learning new knowledge; you’re applying the knowledge you’ve attained.  To bring back the marathon metaphor, it’s incredibly difficult to practice a new running form in the middle of a race.  You need to work on technique individually before you incorporate it into race conditions.  Therefore, using your awareness of your particular weaknesses, the majority of your studying should focus on learning, studying concepts and going over practice questionsin detail.  Only after gaining more confidence with the material should you think about trying another practice exam.

Going forward

It’s best to use practice tests sparingly and primarily as a way to become accustomed to the GMAT’s length and organization.  Take one when you begin studying in order to identify areas that need improvement and then focus efforts on learning: strengthening weakness and becoming familiar with question types.

If you want to, take one or two more a little ways out from the test, but try not to attach too much importance to your scores, just note the general trend.  And for any practice test you take, try to make it as real as possible in order to simulate actual testing conditions.  Do the essay questions and take the allotted breaks.  This way you’ll be more comfortable taking the real test, and you’ll be better able to focus.