GMATPrep Accuracy?

HappilyConfused · Posted: Mon May 07, 2007 1:16 pm Post subject: GMATPrep Accuracy?

I am curious about the accuracy of the GMATPrep practice tests.

I just took the first one and was given a score of 740 with a breakdown of Q 49 V 43. This is despite answering 23 questions correctly and 15 incorrectly in the Quant section (and not all of the incorrect questions were at the end).

Has anyone else experienced a result like this? How strong an indicator is the GMATPrep score?

Thanks,

-HappilyConfused

beatthegmat · Posted: Mon May 07, 2007 3:00 pm Post subject: Re: GMATPrep Accuracy?

Stacey Koprince · Posted: Tue May 08, 2007 12:53 pm Post subject:

Before you go into the real test, make sure you understand the basics of how the test is scored - it isn't about your percentage correct (or incorrect), it's about the difficulty level of the questions you answer. Expect the # incorrect to remain high, no matter what your score is.

Also, the official GMAT has a standard deviation of 29; GMATPrep's standard deviation is not public but can be expected to be worse (that is larger) than that of the official GMAT. If you had gotten that 740 on an official test, this means you would have a 2/3 chance of scoring within 29 points (that is, between 711 and 769) and a 1/3 chance of scoring outside of that range (either lower or higher) if you took it again.

As you can see, the standard deviation of the official test is pretty high already - and all practice tests (even the "official practice" tests) will be less precise than the real thing.