Since October 1, 1997, the GMAT has been offered in a computer-only format, known as the GMAT Computer Adaptive Test, or the GMAT CAT. Unlike a paper test, the CAT adapts to your performance as you proceed through the test. In fact, every person gets a different test depending on how well he or she is doing. Your final score is based not on how many questions you get right but on the difficulty level of the questions you answer correctly.

The test starts with a medium-level question that about half of the test-takers are expected to get right. If you answer it correctly, your score goes up and you get a harder question; if you get it wrong, your score goes down and you get an easier question. This process continues throughout the test. In theory, by the time you get to the end of each section, you'll be getting about half of the questions right and half of them wrong. (We'll cover scoring in more detail a little later.)

Another difference between the CAT and the traditional paper test is that you don't have to register months in advance to take it. Instead, you take the CAT by appointment -- which you can make even just two days in advance -- at an official test center. Simply call 800-GMAT-NOW (in the U.S. and Canada) or go to www.gmat.org to register. If you prefer to sign up the old-fashioned way, you can get the GMAT information application bulletin at a local college counseling office, library, or Kaplan Educational Center (or call 609-771-7330 to have one sent to you).

The CAT is offered six days a week, three weeks out of each month, at 400 testing centers. The centers are located at Sylvan Learning Centers, colleges and universities, and Educational Testing Service (ETS) offices. There are some overseas centers as well. The test costs $190 in the United States, Puerto Rico, and U.S. territories, and slightly more in other countries.