I took 3 MGMAT tests until now.
CAT 1 - 590 (before i started preperation- 3 months ago)
CAT 2 - 690 (3 weeks ago)
CAT 3 - 710 (1 week ago)

Today I took GMAT Prep 1 and scored a 650. Very Painful...

Whats confusing is that I have less number of wrong answers in my GMATPrep test than in the MGMAT test. For example: in CAT 3 (710), I have 17 incorrect answers in verbal. In GMATPrep I have 12 wrong answers in verbal. In CAT 3, I have 14 incorrect answers in quant. In GMATPrep I have 13 wrong answers in quant.

All through the test, I had a good feeling that i am getting more answers correct, but at the end, i am very disappointed to see a less score.

I understand that i should read too much into the scores, but I am confused with this pattern. (with the fact that everybody says GMATPrep is closer to the real GMAT)..

Any suggestions are very appreciated...

Vizay

The score is not based on the percentage correct (well, it is only loosely based on that - obviously, if you get everything wrong, you'll have a low score!). The primary scoring mechanism is based upon the difficulty level of the questions you are answering. So what you saw on your tests (in terms of % correct) is absolutely normal.

You could give the test to 5 people and have them all get exactly the same # right and wrong and yet their scores could range from 400 to 700. You can also have more questions wrong at a 700 than someone else who got a 650 - not a ton more, but a few. The distinction is that you will have answered a harder mix of questions than the 650 person.

And, yes, GMATPrep is closest to the real experience because it is using the exact same scoring algorithm as the real test. Any other practice test (including ours) has an algorithm that mimics the real test's but, of course, is not exactly the same because the algorithm is proprietary - nobody knows what it is aside from the people who make it.

The official test has a standard deviation of about 30 points. I haven't seen a published standard deviation for GMATPrep, but it is either also 30 or it is a little higher, depending upon how similar it is to the official test; I usually think of GMATPrep's SD as around 40. The standard deviation on our test is about 50. So your recent tests look like they are coalescing around a mid-to-high 600's score. Oh - and this may not be your goal score, but this is not a bad score! Everyone thinks they "have" to break 700 but 700 is the 93rd percentile. High 600's (mid 80's to low 90's percentile-wise) is still an excellent score range!