GMAT Tips – How the GMAT Computer Adaptive Test Works (CAT Part 2)

Unfortunately, the test centre's computer likely won't be this nice...

This is the second part of a three part series on the CAT. This post goes into technical detail about the inner workings of the unique test. The other two parts include a description of the Computer Adaptive Test Experience and a section about tips and tricks to help you feel comfortable with the Computer Adaptive Test. My sources include the GMAC website, as well as several SFU MBA students who scored an average 727.5 between the eight of them. This group also wrote up an article on the best GMAT Study and Prep Guides.

The CAT format for the GMAT exam is still relatively new, which means that many potential GMAT test takers still don’t know that the entire GMAT exam is done on a computer. The brains at GMAC have done this in order to create a test which has both increased accuracy and validity over a traditional pencil and paper exam. This makes university admissions departments rely very heavily on the GMAT, maybe moreso than they should. One nice thing about SFU’s Grad Business admissions team is that they look at the entire student and not just at their GMAT score. Lets start by making a list of the more unknown CAT facts.

• Each new question is based on how you answered the last, making the next question harder or easier




• You can’t skip around from each question or go back, once you’ve answered a question it is scored




• There is a large penalty for not answering a question, or not finishing a section




• You only need a basic knowledge of computers to navigate the computer adaptive test




• The essay section of the test is also typed, and while it is usually at the beginning of the test, it could     be placed anywhere

So, now that we have a basic understanding of what the computer adaptive test is, and you’ve read about a test experience, lets get into some more technical detail.

On the GMAT’s Computer Adaptive Test, the computer will give you a new question based on how you answered the last question. The first question in any section has an average level of difficulty (500 level). Closer to the beginning of the sections the increase or decrease in difficulty will be greater, because they want to quickly place you within an appropriate broad difficulty level. With this in mind, it’s important to spend a little bit of extra time on the first 10 questions or so. After that the computer does more of a “fine tuning” job with each question until you reach the end.

This exposes that the test has two measurements to find your final score: number of questions correct, and difficulty level. There is also a third highly important measurement which is not as commonly known. The system will measure your range of cognitive abilities with different question types. For example, in the quantitative section you are measured on arithmetic, algebra, geometry, number theory, statistical reasoning, etc. By consistently answering questions correct in each of these sections, you are reducing the standard deviation of scores between the sections. This makes sense because the makers of the test acknowledge that effective managers are not good at one or two things only, they have a well rounded skill set.

To take this a step further, lets combine ideas and apply them to the verbal section, which takes into account this idea of “zeroing in” on your score with each question type. You should spend a couple extra moments with the first of each reading comprehension, critical reasoning, and sentence correction question. Getting these first questions of each type correct will help boost your score by placing you into a higher level of difficulty. Remember though, one of the most important things on the test is to answer ALL the questions, so do a few practice exams specifically focused on the timing. This will help you determine how much extra time you can dedicate to the first few questions. I have a few GMAT timing grids for anyone who is interested. Feel free to email me or leave a comment if you’re interested.

With this new knowledge comes a BIG warning. If you come across a question in the middle of a section that you think is really easy, do not worry that you got the last question wrong. There are two potential explanations at play here, the first and most likely being that it’s just easy for YOU. Don’t get caught up in the level of difficulty of a question. Something that’s easy for you may be difficult for someone else that studied in a different way. The second explanation could be that it’s an experimental question, slipped in there in order for the test makers to determine the level of difficulty it should have on future tests. Experimental questions are common and can be anywhere, just focus on efficiently answering each question and not falling for an easy trick. Often the most obvious answer is wrong.

Last word of caution, that the sections could be ordered in any way, and may not be exactly like the practice exams. The key to this type of exam is to always be prepared to roll with whatever happens. The computer adaptive test can be used to your advantage if you understand it. For more information, and to view the references for this article go to GMAC’s Test Structure and Overview Page.

Be sure to read the other 2 posts in this 3 part series:

GMAT Tips Part 1 – Computer Adaptive Test Strategies

GMAT Tips Part 3 – Best Practices for Test Day