Which tests are the most accurate?

[InkyBinky]

Does anybody know which tests are the most accurate predictors of real GMAT performance? I took GMATPrep a week ago with no familiarity of the test at all and scored a 650. A few days ago about the Official GMAT Guide and took the diagnostic test (my data sufficiency performance needs work), but have not yet begun studying. And today I took the free Manhattan GMAT test and scored a 710.

As I study over the coming months, I think it would be best to use tests that most accurately gauge the real GMAT so that I know where to concentrate. Based on informal perusal of this forum, I noted several complaints about 800 Score, so I will likely avoid their tests. But what about the others? Princeton, Kaplan, Manhattan, etc... Has anyone performed a study comparing the results of practice tests taken shortly before the real exam versus the real exam's itself? If so, are some substantially more reliable than others? Or are they just about the same?

[TheGmatTutor]

Yes, GMATprep is the most reliable indicator of your score. It's published by the GMAC, the organization that publishes the GMAT.

The Quant section on MGMAT is notoriously more difficult than the real thing. The fact that you scored 650 on GMATprep, then 710 on MGMAT, means you are well on your way to achieving a 700+ score on the actual exam!

[InkyBinky]

Yes, GMATprep is the most reliable indicator of your score. It's published by the GMAC, the organization that publishes the GMAT.

The Quant section on MGMAT is notoriously more difficult than the real thing. The fact that you scored 650 on GMATprep, then 710 on MGMAT, means you are well on your way to achieving a 700+ score on the actual exam!

That's good to hear. My MGMAT score was Q46/V41 (79%ile/93%ile), which I thought was weird because I usually do better with numbers.

[Dan@VinciaPrep]

Yes, GMATprep is the most reliable indicator of your score. It's published by the GMAC, the organization that publishes the GMAT.

The Quant section on MGMAT is notoriously more difficult than the real thing. The fact that you scored 650 on GMATprep, then 710 on MGMAT, means you are well on your way to achieving a 700+ score on the actual exam!

I agree that GMATPrep tests are a reliable indicator of your future GMAT score as long as you take the test under test like circumstances. I don't really think that the Manhattan math is that much more difficult that the math of the actual GMAT test though- I think it may be more computational, but not more difficult. In any case, these are definitely two good sources for practice. You can also use PowerPrep (the older version go GMATPrep), which has good practice questions, and generally gives you a score that is pretty close to what you'll get on the test.