GMAT Strategy

It's also the case that a 30-point change is not a significant change. The people who make the test say that when someone earns any specific score, the range of expected scores is +/- 28 points from that score. So, if you score a 690 one day, you can expect to score anywhere from a 660 to a 720 on other days. (We'll leave aside the question of how valid the test is if the testwriters expect such a wide range...)

As aim said, leaving 8 questions blank at the end really hurts your score. For any questions you leave blank, the test assumes you would have answered them all incorrectly and calculates your score accordingly.

Finally, the reason why it's harder to do the questions on the computer is b/c the test is adaptive and it is constantly pushing you to work at the edge of your comfort level. You aren't seeing as many easier questions as you do when you study from the books - instead, you're constantly working on questions that are right in your range or too hard for you.

When you study, don't only study things that you don't know how to do. Learn how to be more efficient with problems / topics you already know how to do or you won't have enough time to answer the increasing number of harder problems you'll get as you improve.

The paper tests aren't a good use of your time - they're completely different than the CAT. They're much easier and, then, the percentage correct really did matter a great deal to your score. I don't recommend practicing with the old paper tests.

I think our (ManhattanGMAT's) tests are good, of course, and you should definitely get the two free official GMAT practice tests from mba.com. I personally prefer Princeton Review's tests to Kaplan's tests.