Random scores from different exams

[snoopyrichie]

Hi,

I was wondering if anyone can provide insight into a problem I am having.

I am taking Manhattan GMAT, Kaplan GMAT, and regular GMAT (from the makers) practice tests.

I am scoring in the low to mid 600s for the Manhattan GMAT.
570-mid 600s for the Kaplan GMAT.
However, on the regular practice GMAT from the makers, my scores are about forty points higher on average.

Which test is the best gauge for how I will do?

Please advise. Thanks for your time.

[Prasanna]

GMAT prep test is the best available indicator and has a standard deviation of 30-50 points compared to the actual exam.

[brianhoberg]

You will find different deviations from each of those exams. Most feel that the 2 GMAT test from GMAC are the closest indicator available. Kaplan GMAT has been praised for their quant exam questions, but most will indicate they score lower on Kaplan than on others and the questions here are harder than reflected on the actual exam. Manhattan GMAT has been shown to be a good all-around indicator of both verbal and quant questions and make excellent practice tests. Princeton Review had a reputation of being too easy at first; however, I feel this has changed over the past few years and especially within the last year in their 2009 guide. The PR exams, while touted as easier than the other exams, does give a good indicator as to your weak points and provides a quality review of the exam material especially if you have been away from quant for a long time (like myself).