Scoring Algorithm

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Scoring Algorithm

by ayousefi » Wed Dec 11, 2013 6:14 pm
I had couple of questions about the scoring system.
Does GMAT increase the grade if you finish early on a section? ( The reason is that I took two GMATprep tests and in both I had only one mistakes in Quant but in one I got 50 and in the other I got 51)
My other question is about the scoring. I looked at my verbal scores and I noticed that the scores are higher when I do not make mistakes in early questions even if I have more mistakes in later questions. On the other hand, for the exams that I made fewer mistakes but even one of them is on early questions my grade was lower.
Is there anyone have any thoughts. I have the exam on friday and your respond could help improving my strategy.

Example (verbal)
Score 42: 7 mistakes Q numbers: 10 18 22 30 34 36 39
Score 42: 8 mistakes Q numbers: 10 14 15 22 23 31 39 41
The odd one:
Score 40: 5 mistakes Q numbers: 3 11 18 19 32

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by David@VeritasPrep » Thu Dec 12, 2013 4:58 am
Your test is coming right up so you need to know a couple of things!

1) The test does NOT credit you for finishing early. Do not attempt to finish early. Follow your timing strategy and use your time wisely. If you happen to finish early (I often finish the Verbal section with 15 minutes to go but that happens naturally) Do not try to push it and finish early unnaturally.

2) It is really hard to get a 51 on the Quant section. Remember that there is such a thing as a "high 50" which is closer to a 51. So I imagine that in terms of what each contributes to your 800 score the 50 and the 51 would be really close even though the percentiles seem to be the 89th and the 97th.

3) On those verbal scores...on the verbal side the scaled scores are very close to each other. Not as much of a spread so a 40 (the 90th percentile) is close to a 42 (the 96th percentile). The difference is not so much when you missed the questions - nor as you can see is it the number of questions that you missed - but rather it is the difficulty level of those questions. Quite simply, you must have missed lower level questions on the test that gave you a 40. Just be careful and focus. I will agree that it is even more important not to miss easier questions early on each section since that impacts the questions that you receive later.

For YOU in particular - since you seem to be headed for a 750 or above - do not do anything drastically different, you are doing great! Just understand that you get no credit for finishing the math with lots of time left, and for the verbal keep focused so that if you do miss questions they will be very difficult ones and therefore will not hurt your score as much.

Will you please report your scores after your test? I am really curious to see how these great GMATPrep scores translate.
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by ayousefi » Thu Dec 12, 2013 9:42 am
Hi David,
Thanks for your thorough advice. I agree that 50 and 51 are really close, in this case only one mistake for both scores. However, the score goes from 770 to 740 as it goes from 51 42 to 50 40. Anyway there is nothing to do about it and I agree trying to game the algorithm will not work as I hardly finish verbal on time

I will hit you up here as i got the grade

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by David@VeritasPrep » Thu Dec 12, 2013 12:53 pm
However, the score goes from 770 to 740 as it goes from 51 42 to 50 40.
This is not entirely true...

Both your scaled scores and your overall 200-800 scores are based on your "raw score" - which is essentially your percentile (the GMAT uses the term "theta" but it works just like a percentile). The way that the test is scored is that the test calculates your "theta" (compared to tens of thousands of people who have taken the GMAT) THEN the test gives you an overall score and the scaled scores based on that raw score / theta.

What this means is that many raw scores will show up as a single scaled score. But when the 200 to 800 score is calculated the raw scores are used.

Please read this statement from GMAC "Your total score is based on raw performance on both the Verbal and Quantitative sections. A range of raw scores will map onto a single scaled score, but since the Total score is based on the raw performance, greater differentiation is possible."

In other words, there are many raw scores that yield a 50 on Quant and some of those scores would certainly when combined with a 40 on the verbal give you a 750 instead of a 740 and if the verbal score is actually on the high side of say a 41 you might even sneak out a 760.

Basically what you said is right, no games. Just do your best. The only reason I went into this detail is that I just wanted you to know that it is not such a big swing based on one or two more questions wrong. You should not feel any pressure. You will do great! My guess based on your practice tests is 750-760. Good luck!
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