Then there is the scoring system. Not all questions count equally. This is because the jumps in score are more extreme at the beginning of each section. In fact, two test takers can get the same number of questions right but have very different scores. Here's how it works:

Total scores on the CAT range from 200 to 800. The first question in each section is worth 80 to 100 points. You start each section with a score of 500, so if you get that first question right, your score goes up to about 600; if you get it wrong, your score goes down to about 400. The second question is worth 60 to 70 points. This means that if you get the first two questions on a section right, you're looking at a score of about 670, but if you get the first two wrong, you've got a paltry 330. Here's the odd part: If you get the first question right and the second wrong, you've got a 530, but if you get the first one wrong and the second one right, you've got a 470. The relative weighting of questions affects your score that quickly.

Of course, the scoring gets more complex as you answer more questions, but in general, after the first five questions of a section, you're just fine-tuning your score. If you answer the first five questions correctly, you'll be working at a level well above 700. If you get the first five wrong, you're well below 300 and will likely get easy questions for the rest of the exam -- the kiss of death on the CAT. You can recover from answering a few early questions wrong, but you'll need to get a long string of questions right, as later questions are worth less.

As confusing as all this may sound, your score on the CAT is likely to be very similar to what it would be on the pencil-and-paper version of the test. Before switching over to the CAT, ETS pretested and normed it to make sure the scores were comparable.

There are definite advantages to the CAT. Instead of scheduling your life around a predetermined date, you can sign up to take the test whenever is convenient for you. And, unlike with the pencil-and-paper version, you can see your scores immediately after completing the test. Last, many people prefer to type their essays. "With the essays... I loved the computer version," said Kevin Fleming, who took the CAT when ETS was pretesting it. "I type probably six times as fast as I write, so that helped a lot. I liked being able to cut and paste and make clean edits."

Of course, there are some downsides to the computerized GMAT. Not being able to go back to a question is the main one. The experimental questions also seem to unnerve students more on the CAT than on the paper-and-pencil version. On the CAT, "if you think you got a problem right, you're anticipating a harder one," explains Will Peppo, who is currently studying for the exam. "You might have gotten a hard one right, and then you get an easy experimental question. And then you think you might have gotten the last question wrong. That's tough psychologically."

Finally, you have to use separate scratch paper when taking the CAT. "You have to take the information from the screen that you need and somehow transfer that to the paper," says one student. "For example, in reading comprehension, you can't circle key words." Plus, you have to scroll through the reading comprehension passages because you can't see the whole thing at once on the screen.

Interpreting Your Score

GMAT score reports contain four separate scores: a quantitative score, a verbal score, an analytical writing score, and a total score. The quantitative and verbal subscores range from 0 to 60; in recent years, the average subscores have been between 28 and 32. Scores below 10 and above 46 are rare. Analytical writing scores go from 0 to 6 (6 is high) in half-point increments. The recent average has been between 3.5 and 4.5. The total score, which is what most people consider as their GMAT score, is based on the verbal and math scores and ranges from 200 to 800. The average total score hovers around 500.

Here are some sample percentiles to help put these numbers (representing total scores) in context:

99th percentile -- 720 or above
95th - 670
90th - 630
80th - 590
75th - 570
50th - 500

The report lists your three most recent GMAT scores within the past five years. GMAC (the General Management Admission Council, which administers the test with ETS) will report older scores if you request them, but will add a cautionary note that those scores may not reflect your current abilities. If it's been five or more years, some schools may require you to retake the test.

As soon as you have finished the exam, you can choose to either see your unofficial score (which is almost always identical to the official one) or cancel it. If you cancel your test, it won't be scored and will appear on your GMAC report as a canceled score. No one, including you, will ever know how you did. Don't worry -- B-schools won't think less of you for canceling a score. If you choose to see your score (which won't include your writing score -- that will come with the official report) you can also select additional schools to which you would like your scores sent. The official score report should arrive both at the schools and your home within about two weeks of the test.

Hint: You can pick five schools to send your scores to when you register for the GMAT. Even if you're not sure where you're applying, pick the most likely places; these first five score reports are free, but additional reports cost $15 each.

How Well Do You Have to Do?

To be considered by elite schools, you need at least a 600. But the scores at the very best programs are much higher: The average scores at Stanford and Harvard last year were 722 and 699, respectively. However, it's possible that schools are looking more at percentile scores than numeric scores right now because the CAT is so new. "Schools are very cautious because they don't know how to evaluate it," says a Kaplan instructor. The 90th to 99th percentile usually gets you considered at the top programs. In general, the verbal and math subscores are less important than the total score, although some schools will look at the breakdown to see that a certain skill -- usually quantitative -- is up to par.

Many of the top schools will consider only your highest total score from a single test date. So if you got a 650 the first time you took the test and a 700 the second time, 700 will be the score they look at. Around 40% of schools will combine your highest verbal, quantitative, and total scores if they're from different test dates. A few will look at only your most recent scores, and others will average your scores. Ask schools about their policies.

Incidentally, lest you think your score no longer matters once you're admitted to school, keep in mind that some recruiters (McKinsey is one) will ask to see your GMAT scores.

Hint: You may have heard the rumor that the top schools don't even look at writing samples because they have such a huge load of applications to review. While it's not untrue -- according to a former member of the admissions committee at Harvard Business School, the writing score is generally only used to break a tie between two students -- don't blow off the writing section. A stellar score can help you if you're on the borderline.

Preparation Is Everything

Not to sound like your mother, but if you hope to do well on the GMAT, you really do have to prepare. By studying and familiarizing yourself with the test, you can substantially improve your score. For example, grammar questions comprise about 40% of the verbal section of the GMAT. If you haven't thought about dangling modifiers since eighth-grade English (and we hope you haven't!), you'll find that you can boost your score a lot just by reviewing a few basic rules. Try to allot at least three months to study for the GMAT -- though anything is better than just breezing into the test center unprepared.

The best method, as with any standardized test, is to practice with past exams. Consider purchasing The Official Guide for GMAT Review, published by ETS. It's the only resource that contains official past GMATs. Even better, buy the PowerPrep software package, also produced by ETS, which has two practice CATs made up of the same questions as in the Official Guide.

Hint: It is a little known fact that ETS will allow you to take a practice GMAT CAT at one of the test centers. Take advantage of this offer.

Unfortunately, the resources published by ETS contain only a few tests; you will probably need more practice tests than they provide. Also, these tests are from a few years ago and are somewhat dated. For example, some math concepts that were not on previous exams have been added in recent years.

That's a compelling argument in favor of taking a GMAT course, a popular study method among business school applicants. Although test preparation has become an industry in itself -- and these companies have a vested interest in getting you to believe that you need to take one of their expensive classes in order to do well on the GMAT -- it's their job to monitor the exam, identify common traps, and develop strategies for finding correct answers. GMAT courses run around $1,000, but they can be worth it if you go to all of the classes, work through most of the home-study material, take advantage of workshops, free tutoring, and extra help special sessions, and take simulated practice CATs at the test centers. (Keep in mind that these are tests created by the companies, so while they closely mimic the GMAT, your score on and experience with them won't quite be the same as an actual exam.) Also, some people find that if they pay money for a class, they're more likely to attend.

Peppo says that his prep course helped him in "being able to see a problem and identify the type of question and know exactly how to break that problem down.... You kind of know already what they're looking for." Another benefit was "realizing that you can get some of the questions wrong and it's not going to affect your score that much. If you're really stuck on one, don't burn time -- move on."

Courses can also teach you how to approach the Analytical Writing Assessment, which is graded by both a person and a computer program called the "e-rater." Your score is the average of their two grades; if they disagree by more than one point, a second person looks at your writing as well. Besides checking for grammar, spelling, and usage, the e-rater looks for characteristics like disparate sentence length, stylistic variations, and clear structure, with the main idea at the beginning of each paragraph. Classes can teach you what the e-rater is looking for.

Here are some things you can do to get the most out of your GMAT course:

• Work on your endurance. The GMAT is a long test, so you should take lots of practice tests.
  
• Simulate test conditions exactly. Time yourself strictly, don't cut out the writing section, and practice at the same time of day your test is scheduled for.
  
• Review your practice exams thoroughly. Go over all of your answers -- even the correct ones -- and the explanations your study guides provide. This will help you reinforce concepts and review formulas and shortcuts.
  
• Don't work just on your weaknesses. Points are points, no matter where you gain them, and you don't want your strengths to get rusty.
  

Classes aren't for everyone, though. If you are well below average in math, for example, you might need more specialized help. In that case, you might call a local high school or college for the name of a tutor or a basic review course. Similarly, if you are in the upper 20th percentile and have only a few areas of weakness, you might consider a private tutor or a targeted, tracked class. Several companies offer private tutoring for about $100 – $150 an hour. Graduate students, teachers, and independent tutors often charge less.

The advantages of tutoring are obvious: flexibility and individual attention. You get to choose the time and place to meet and, more important, you can focus on the areas where you need help. Private tutoring can also be cost-effective because, although hourly rates can be high, you only pay for the hours you really need. The disadvantage is that it can be hard to gauge whether a tutor has a good background and expertise for what you need and whether he or she will truly be helpful. If you need help in more than one area or just want a general brush-up, a course might be a better choice.

Test Day Tips

Pick the best spot. If you live near multiple test centers, check them out before registering, as some are quieter and more organized than others. Once you get there, make sure you have enough light, adequate space to write, and a comfortable chair. If you don't, ask for them. Also, make sure that your computer, mouse, and keyboard are working; you're given a short computer tutorial beforehand which should give you time to do this. The tutorial is also a good time to write down formulas, strategies, and mnemonic devices on your scratch paper.

Don't cram the day before the test. There's not much you can do to help yourself at this point, and you will just stress out. Review a few key points, gather what you will need for the next day, and take the night off.

Pack reinforcements. Besides the standard items like your admission ticket, a photo ID, and pencils or pens for scratch work, you'll want to bring a small snack and extra clothes with you. Dress in layers, as test centers are notoriously either too hot or too cold. Don't bring scratch paper, calculators, or digital watches, none of which are allowed. (Watches with hands are fine.) Your proctor will provide scratch paper, and there's a clock on your computer screen.

Pace yourself. Because the first five questions of each section are so important, start slowly (although there are limits to this if you are aiming for a very high score), and then speed up. The onscreen clock automatically stays on during the last five minutes of a section, but it can be turned on and off during the rest of the test. Turn it off during the first five minutes so that you don't feel pressure while answering these crucial questions. Guess strategically. Guess only if you are really stumped or tight on time: If you have 6 to 10 questions with less than five minutes left, try to eliminate at least one wrong answer before guessing. If you have 11 or more questions to go with less than five minutes left, guess randomly until you get to the last question, and spend all of your remaining time on that one.

Take a break. The CAT includes two optional five-minute breaks. Take them. Don't outsmart yourself. Don't get too caught up in your knowledge of how the test is scored and overanalyze the difficulty level of every question. If you get what seems like an easy question, don't panic: It might be a trick problem, an experimental question, or just one that's simple for you but hard for others. "Always concentrate on the question at hand," says one GMAT tutor. "Don't worry about the one before it or the one after it."

Don't rush to retake the test. Of course, it's always possible that you will get really flustered or have some other experience that causes you to score poorly on the test. But think twice before taking the GMAT again. Do you have a legitimate reason to think your score would improve a second time around? Was your score low because you weren't familiar with the test format and types of questions? Do you have one or two clearly identifiable weaknesses that targeted study could improve? If so, you may be a good candidate to retake the test. The same holds true if there were extenuating circumstances -- a personal trauma, illness, uncontrollable nerves, or a poor night's sleep.

However, if you absolutely killed yourself studying the first time, you may be too burned out to do it all over again. Score jumps of 100 or more are unusual, and your score won't just magically go up because you've taken the test before. If you've taken the GMAT twice or more already, you've probably done all the improving you're going to do.