GMAT CAT Format
The computer version of the GMAT is in the CAT (computer adaptive test) format. GMAT CAT format means that the difficulty of the next question depends on whether you have correctly answered the previous one. Each section of the GMAT exam starts with a medium question and, depending on whether you answer it correctly or not, you will get a harder or an easier question. This repeats after the second and the third question and so on until the end of the section.
Because the GMAT CAT test provides the next question only after it has scored the previous one, you will not be allowed to skip questions or return to them once they have been answered. To achieve the highest score you have to answer as many hard questions as possible.
What does the CAT Format of the GMAT Mean to Me?
It is important to answer the first several questions correctly, since GMAT is a CAT test and will increase the difficulty of questions, which, in turn, increases your chances of getting a higher overall GMAT score. As you can see on the graph below, both the Red and the Green test-takers answered 10 questions correctly out of 20 (shown by a square mark). But since the Red student answered the first several questions correctly, most of his subsequent correct answers are to questions in the 600-700 difficulty range. Therefore, his score will be higher than that of the Green student, who answered the same number of questions correctly, but mostly in the 200-400 difficulty range.
On the graph above square marks stand for correct answers, and circles stand for wrong answer. As you can see, every correct answer increases the difficulty and, consequently, the value of the next question, while every wrong answer results in an easier next question.
Therefore, we recommend that you take extra care and time on the first several questions, because if you answer them correctly your chances of getting a high GMAT score increase. However, this alone does not ensure a good score since you have to answer the rest of your questions too. If you relax after the first questions and get most of the rest wrong, you will still end up in the lower part of our graph, answering easier questions for a lower overall GMAT score. If you answer the first several questions wrong, do not get frustrated, you can still answer the rest correctly and receive a high score.
The above graph does not precisely reflect the GMAT CAT algorithm, but the idea is the same.
As you have probably understood so far, it is vital that you answer as many hard questions as possible, so whenever you see a hard question, think of how you can find an answer and do not just guess and move on.