The GMAT CAT: Commentary And 11 Rules Of Engagement

Since the GMAT CAT is so new, I intend to cover this topic in more detail than the previous topics. I have developed a number of rules specific to the GMAT CAT. You will find them below. I will first provide the commentary justifying the rule. I will then state the rule. I encourage you to read both the commentary and rule.

First by way of background.

Computers have transformed our way of life. The new information age has resulted in a complete realignment of the way that people live. There is no part of society that has been untouched by computers. In the early 1980s it became clear that computers were going to assist in teaching standardized tests. In the early 1990s the GRE (Graduate Record Exam) began to be administered on computer as a computer adaptive test. Law Services is currently conducting a study to determine if the LSAT should be administered as a computer adaptive test. In the world of standardized testing the trend toward computer adaptive testing is clear. But what is meant by "computer adaptive" and to whose advantage is it?

What Is A Computer Adaptive Test?


A "computer adaptive test" is administered by computer, taken on a computer and adapts it questions for the purpose of determining the "ability" (whatever that is supposed to mean) of the test taker. By generating questions and evaluating the test taker's answers, the computer will gradually determine the ability level of the test taker. This ability level, once determined, is translated to score on the 200 to 800 scale. How does this happen?

Imagine you are seated at the terminal to begin the GMAT CAT. At the beginning of the test the computer has no information about your ability. It is the job of the computer to determine your ability by generating questions, and based on your response, to determine an appropriate follow-up question for you. This necessitates two important departures from traditional "paper and pencil" based testing:

Rule 1 - The computer will administer different questions to different test takers. Computer adaptive tests are not standardized tests in the sense that all test takers get the same test.

Rule 2 - You must answer every question at the time that it is presented to you. Otherwise the computer will not know what question to generate next. There is no opportunity to skip around.


The inability to skip questions has resulted in a premium on better basic math skills. The GMAT does assume competence in many areas of background math. These topics do not exceed what is commonly taught in grade 9 or 10. But, many GMAT test takers have forgotten these topics. On the "paper and pencil" test if a question was based on a forgotten concept one could skip it and find another question. On the CAT the question must be answered then and there! This means that a review of "GMAT Math" is much more important than in the old days. Some test takers have reported seeing certain question types that were not anticipated in the "paper and pencil" GMAT format. Examples include, (but are not limited to) probability and permutations. "GMAT Math" is described (in terms of topics) but not taught in the "Math Review" section of the Official Guide For GMAT Review. You would be well advised to review every topic that is described in the "Math Review" section of the Official Guide For GMAT Review. Bottom line:

Rule 3 - The CAT makes a review of "GMAT Math" much more important!

Commentary: What happens when you get started. The computer begins with an average question. If you answer it correctly the computer has a higher estimate of your ability (your score goes up) and you are "rewarded" with a harder question. If you answer it incorrectly the computer has a lower estimate of your ability (your score goes down) and you are "penalized" with an easier one. This means that:

Rule 4 - It is to your advantage to be on the receiving end of hard questions.


In theory, the computer is generating questions for the purpose of finding your correct ability level. With each additional question the computer acquires more information about that level. The less information the computer has (the fewer number of questions you have answered) the more your answer to the next question will tell the computer about your ability. But, the more information the computer has (the more questions you have answered) the less your answer to the next question will tell the computer about your ability. This means that in evaluating the test taker:

Rule 5 - The answers to earlier questions will impact more significantly on your score than the answers to later questions! Your answers to questions during the first half of each multiple choice section will impact much more heavily than the answers to the second half. Clearly one should be much more reluctant to guess on earlier questions than on later questions!


How much more significant is the answer to an earlier question than the answer to a later question? The exact algorithm for determining GMAT ability is a closely guarded secret. All claims about the exact number of points that a given answer will impact on your score should be met with skepticism. Claims about the answer to the first question raising or lowering your score by a precise number of points are pure speculation.

Rule 6 - Since only GMAT has access to the formula that determines GMAT scores, ignore all statements that claim to quantify with precision the effect of specific questions.


In theory the computer should continue to generate questions until it is has determined the ability level of the test taker. It is obvious that the more information the computer has the better able it is to determine a score. Must the test taker provide answers to all 37 quantitative questions and all 41 verbal questions to give the computer sufficient information to determine a score? According to GMAT:

"You must respond to both essays and each multiple section of the test to get your scores reported. If you do not finish the multiple-choice sections, you will get a score that reflects the portion of the test that you have completed."

Rule 7 - Test takers will receive scores if they fail to answer all of the questions.


Remember, the more information the computer has, the better able it is to determine the score. There is no requirement that the test taker answer every question. But, is it to the advantage of the test taker to answer all 37 quantitative questions and all 41 verbal questions? Although GMAT does not specifically advise test takers to answer every question, it does make the following two suggestions:

"- Guess, if you do not know the answer or if the question is too time consuming."

"- Pace yourself so that you have enough time to answer every question. Pay attention to the number of questions and the amount of time remaining during your testing session .... On average, you have 1 3/4 minutes for each verbal section and 2 minutes for each quantitative section. (If you do not finish in the allotted time, you will still get a score as long as you've worked on every section.)"

Rule 8 - GMAT strongly encourages you to answer every question.


Okay, so GMAT encourages you to answer all questions. But, what if you don't. Is there a penalty? How will the failure to answer all questions impact on your score? Common sense dictates that a failure to answer questions will hurt your score. Consider this hypothetical situation. John answers 10 of 37 questions getting each of them correct. Linda answers all 37 questions getting the first 10 right and the last 27 wrong. Assuming John and Linda had identical scores after the first 10 questions, should John be rewarded (relative to Linda) by failing to provide the computer with more information? Obviously not. To not answer all the questions is to fail to provide the computer with all the information that it wants. In addition, it is reasonable to assume that John spent more time on each of the 10 questions he answered than Linda did on each of the 37 questions she answered. Therefore, one could argue that Linda achieved the same results on the first 10 questions with less time. Although GMAT does not take an official position, it seems reasonable that there be a penalty for failing to answer questions. Assuming that there is a penalty, what should that penalty be? Once again, this is purely speculative. Some commentators have suggested that the failure to answer a question correctly will result in a deduction that is higher than the deduction for simply getting the question wrong. In addition, it seems likely that the more questions omitted, the higher the deduction for not answering the questions. (The more unanswered questions the less information the computer has to determine your ability.) It is likely that there is more to be gained than to be lost by selecting an answer for every question.

Rule 9 - Take steps to ensure that you provide an answer for every question. Guess if necessary putting the same answer for all random guesses.


The old "paper and pencil" format had one section that was composed entirely of experimental questions that would not affect your test score. Experimental questions have been retained on the CAT. They will be included in the 37 quantitative questions and the 41 verbal questions and will not be identified as being experimental. This implies that not all 37 of the quantitative or 41 verbal questions are needed for the computer to determine your ability. It would be unfortunate to spend too much time on any question that is experimental.

Rule 10 - While taking the CAT be conscious of the fact that you will encounter experimental questions that will not influence your test score.


Finally, remember that the CAT is designed to find questions that are of the appropriate level of difficulty for you. If you get a question right you will be given a harder question. This means that the test will feel hard for everybody! The fact that you find the test difficult is not an indication that you are doing badly. It is an indication that the test is determining your ability. In this respect the CAT is different from the "paper and pencil" GMAT where there were pockets of questions that some test takers found to be easier.

Rule 11 - The GMAT CAT is a physically and emotionally demanding experience for all test takers. Do not allow yourself to become flustered. Make sure that you are well fed and well rested prior to the test.


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