Big difference (50 pt diff) between MGMAT and GMATPrep score

[devenh]

Hello,

I just finished taking a test using the official GMATPrep software and I noticed a big gap between the scores I have been getting on the Manhattan GMAT tests and the score I received the GMATPrep test. Over the last week I have taken 4 tests. 3 tests were MGMAT tests and one was a GMATPrep test. On my last three mgmat tests i scored a 660, 670, and a 700 (in that order), and I was feeling pretty confident until i took a gmatprep test today and flopped with a 650. the troubling part about the 650 is that i actually felt i did better on it than any of the other manhattan gmat tests, and i actually answered a greater percentage of the questions correctly in both verbal and quant. i'm very confused why my score dropped, and what should i do to fix it?

here is a break down of the scores i recieved over the last week:

sunday: 660, Q44, V36
tuesday: 670, Q45, V36
thursday: 700, Q39, V41
saturday: 650, Q35, V45 ---> this was the gmatprep test

on my manhattan gmat cat tests in the quant section i was getting around 20 questions correct and around 17 questions incorrect, on the gmat prep test i actually got 24 questions correct, 13 questions wrong, (which is much better than my mgmat test) and 1 question blank. does leaving one question blank really fluctuate my score by almost 50 points?? in verbal i also did relatively well on the gmatprep test compared to the mgmat test. i answered all of the questions in verbal and i only missed 11 questions.

my question is...why did my score drop even though i answered more questions correctly? one theory i have is that my score dropped because on the gmatprep test i missed 5 questions out of the first 10 on quant. the gmatprep seems very unforgiving, so once i missed 5 out of the first 10 the gmatprep test did not give me any hard questions to allow me to fully redeem myself. however, on manhattan gmat exams even when i miss a few questions early in the sections the mgmat test gives me enough hard questions to allow me to redeem myself.

could there by any other explaination for my drop in score??

for all the GMAT practice tests I made sure (mgmat and gmatprep) i kept testing conditions as close to the real test as possible: no breaks beyond the two 10-minute breaks, i completed all of the essay sections, and i took the tests at the same time each day.

[StaceyKoprince]

To begin, a few good things to know:

- 50 points is not a big difference in score between these two tests. In general, the standard deviation of standardized tests is pretty high - about 30 points on the real test and about 50 points on ours.
- taking tests more frequently than once a week just increases the likelihood that you'll tire yourself out (and then your score will drop)
- the tests are not scored based upon percentage correct, so concentrating on that doesn't actually help you figure out what's going on (or how to get better)

Now, although a 50-point difference is not that major of a difference, when I look at the quant and verbal subscores, there is something problematic going on there. Your quant score dropped about 30 percentile points, and that is a significant difference. So we do need to figure out what happened there. Read this article, do the analysis described, and come back to post here again:

http://www.beatthegmat.com/a/2009/10/26/my-score-dropped-figuring-out-what-went-wrong

If you want to gain a better understanding of how the scoring works, you should read the scoring section of "The GMAT Uncovered," our free e-book about the GMAT. If you already have an account with us, the PDF is already in your account; just log into your student center and look for it.

If you don't really want to learn a lot of detail about the scoring, that's okay, too. Just know that the scoring is primarily based upon the difficulty levels of the questions you're answering, and everybody answers approximately the same percentage of questions correctly. In fact, someone could have a few more incorrect answers than you but still get a higher score - if the questions that person was answering correctly were of higher difficulty.

The CAT (real, GMATPrep, or MGMAT) does not penalize you more for getting earlier questions wrong. Also, do know that leaving something blank does have a fairly significant negative effect - each blank question costs you about 3 percentile points on average. Your quant score dropped a lot more than that, obviously.

Let me ask you: why did you leave one blank? I'm guessing you were running out of time. Did you only notice you were running out right at the end, when you were on that last question? Or were you already rushing on some number of questions before that last one? If you were rushing, then you likely missed questions that you might have gotten right. That situation also makes it more likely that you had a "cluster" of 4 or more wrong in a row, and there's a larger effective penalty when you have a lot of questions wrong in a row. So I think it's possible that your score drop might have been more indicative of a timing problem than anything else.

I'm really glad, by the way, that you've been taking CATs under full official conditions - keep that up. Just know that CAT exams are really good for (a) figuring out where you're scoring right now, (b) practicing stamina, and (c) analyzing your strengths and weaknesses. The actual act of just taking the exam is NOT so useful for improving. It's what you do with the test results / between tests that helps you to improve. So spend less time taking tests and more time figuring out what you need to improve (and improving!) before you take another test.

You can use this article to help you analyze your tests, by the way:
http://www.beatthegmat.com/a/2009/09/23/evaluating-your-practice-tests