For example lets say a person comes and tells you "I take a bath everyday" you tend to think " well good for him". If the person says " I take a bath 2 times a day" you think " well! Thats nice! he is clean". Lets say a person says " I take bath 9 or 12 or 15 times a day" you dont think any different about the person. You know he is clean and he takes bath. The fact that he/she bathes 15 times a day doesn't make the person any special. On the other hand if the person does not take a bath you'll think the person is unhygenic.
So GMAT is like bathing. If you score over 700, you are clean and hygenic enough for B School. Below 700 - yes you stand a chance of failing the hygene test. The more you score in GMAT like 760 770 and 790 - while is impressive - will hardly turn around your application decisively. Taking the test again after scoring 720 to improve it to 780 is just doing charity to ETS. And they are already rich. The Universities know you are clean so dont waste your time retaking after a 700+ score. Spend that time on getting your essays in shape. That is more important. Last year alone I have seen a 800 GMAT being rejected and tossed around by many schools in the BW forums. I personally know of 2-3 people who did not get anywhere with a 790 GMAT.
Having said all this - the GMAT score does play a factor in your visa and you will put it in your resume (in some schools) when you search for jobs during B School. So it plays a factor. So while you are writing it make sure you write it well.
The adaptive test Factor:
So I have taken the paper test and this computer adaptive test. I feel the computer test is a bunch of BS. I agree to an extent that it is a more accurate reflection of your score than the paper test. But the paper test is slightly difficult and requires more stamina. The computer test increases in difficulty if you are getting the initial questions right. It maintains or lowers its difficulty level if you get the first few questions wrong. Paper based tests increase in difficulty regardless of how well you are doing. So in a computer based test the key thing is to make sure you pace yourself very well in the first few questions and make sure you do them right. You get heavily penalized for getting the first few wrong. This is very critical.
Anyway the GMAT has 4 sections.
2 Writing Sections: These 2 sections are scored for a total of 6 points. It does not make a difference if you score 6/6. But you have embarassed yourself if you score less than 4.5. This philosphy is representative of GMAT as a whole. You only stand to lose by doing badly. The gains are less. Follow the Kaplan Verbal reviews tips on how to write this essay. That book was priceless in this regard.
Quantitive: There is no specific advise that anyone can give on this section. I wish I had taken my GMAT after my CAT. I would have totally nailed the GMAT quant. The Quant portion is simple enough if you compare it with CAT. But unlike CAT in this section - you can't afford to make mistakes at all. You have to get all the questions correct (at least almost all of them). Even if you get one or two wrong its a big impact. So dont take this section easy. Find out the types of problems asked. If you do not know how to tackle those problems (you will not initially) then have a record of new learnings and memorize it.
Verbal: So This is the make-or-break section for most engineers. This section is pretty tough. Tougher than the CAT verbal. The sentence correction questions are ball-breakers. RC was the key element in GRE. Here it is sentence correction and RC. Comprehension still needs some strategizing and practise for the GMAT also. This continued to be my nemesis even in the GMAT. I'd highly recommend Priceton Review and Kaplan for verbal. They have a systematic approach for sentence correction questions.
You dont need to memorize the word list. It has no relevance here. The main thing is to make sure the sentence correction and RC is in control. Priceton's 6 types of sentences helped me a lot.
Timing the test: I did not have a problem with the time. Initially it is better to do the full test and then crank it up to meet time limits.
In terms of when to take the test - see this was my problem. I had kept Dec 31 as the date ( nobody takes it then, you can leverage christmas holidays and the date was easily available) and thought I'll prep from Vijayadasami (Oct). But thats only in theory. Work will come and beat the shit out of you. It always does. My toughtest project in my work exp came during GMAT. This happens for a lot of people. So account for this. I think 1 month of finding your feet and 2 weeks of test taking should be sufficient.
Which Books to buy?
I am a big book buyer. I felt I needed a lot of tests. Tests are bundled with books. So if you want to take 20 tests you have to buy books. I'd highly recommend the following -
1) Princeton GMAT Reviews
2) Kaplan GMAT
3) Kaplan Verbal
4) Princeton Verbal
5) GMAT ETS - The Big Book
8) Petersons GMAT Guide ( has 6 exams in it)
9) Power Prep - 2 Tests comes to you as free when you register.
1. The real test will be much harder than any other test that you might've taken before.
2. During the test - Even if you feel you are doing badly - you may not be. So don't fret and really start doing badly.
3. Never run a ball-by-ball commentary when you are writing the test. Its disastrous.
4. The power-preps are way too easy than the actual tests. If you score a 790 in both those tests don't feel smug.
5) Sentence correction and Comprehension will make-or-break the engineers taking GMAT.
6) Need passport to write the exam.
7) If you see a score stagnating between 2 practise tests. Back off. Post-mortem your exams and come back. Taking 200 tests doesnt earn you even bragging rights.