Study and Strategy questions relating to the GMAT.
aloksanghavi
 
 

Got 780 in CAT Test3

by aloksanghavi Wed Mar 21, 2007 8:29 am

Hi,
I gave the CAT Test 3 and got 780 but i am confused how this is possible. I got few questions wrong in Verbal but still have a 51 while Math wasnt all that good but still have a 48. I dont know how close this score is to what i deserve but is there any way to say if this score is really a measure of how i performed on the test? I am just couple of weeks away from the exam and so would like an honest opinion about these tests as i also want to decide whether i should take the rest of the CAT tests.

Thanks,
Alok
ayang
ManhattanGMAT Staff
 
Posts: 42
Joined: Thu Jul 31, 2003 1:31 pm
 

Practice Test Scoring

by ayang Wed Mar 21, 2007 11:09 am

Alok,

It has been the case that students have scored similarly to you on the MGMAT CAT and had strong, but not stellar results on the actual GMAT.

We’ve been monitoring the scoring closely. So far, our data is showing that the highest score a student gets on one of our practice tests overshoots the score on the real GMAT by about 10-15 points. We haven’t yet made an adjustment to the algorithm because we haven’t yet confirmed this is statistically significant. We are looking to make an adjustment, though, as soon as we can confirm the level of the inflation.

The standard deviation of the difference (between the practice test score and the real GMAT score) is 50-60 points. We would like to reduce this and are taking steps to do so, but note that for many reasons, a practice test can never perfectly predict the GMAT. For one thing, the GMAT itself has a standard error of 29 points - meaning that only 2/3 of the time would you expect to get within ~30 points of your "real" score. Also, we write simulated questions and use a simulated algorithm - neither of which can we calibrate perfectly to the real GMAT. Finally, YOU are a big variable. When a student takes a practice test - even the GMATPrep, which does use the real algorithm and real questions - the student knows that it’s practice. The fact that the real GMAT counts is a factor that no practice test can simulate, naturally.

Our algorithm mimics the algorithm of the real GMAT but is not exactly the same, true. GMATPrep does use the real algorithm, but the pool of questions does not seem to be anywhere as deep as that of the real GMAT. The practical effect of this "shallowness" of the pool is that high performance deviates more from the theoretical 50-60% right that pure IRT (item response theory, the theory behind the algorithm of the GMAT which we understand quite well) would predict. In simpler terms, if the pool is shallow, the algorithm cannot give you "tough enough" questions while still meeting the constraints of content breadth and format breadth. Thus you would expect to get more right on a shallow-pool GMATPrep than you would on the deep-pool real GMAT. Our pool is deeper, which leads to a closer fit to the 50-60% right that pure IRT predicts.

We will continue to invest time and resources into perfecting our algorithm and our question pool. We believe we already have the best test out there besides the GMAT Prep (which of course uses real questions & the real algorithm), but we won’t rest on our laurels.

All that said - the actual score is the least important piece of information from any practice test. You should neither be elated by a high practice test score nor deflated by a low one. You should use practice tests to do two things: (1) identify relative strengths and weaknesses, and (2) gain experience with the format of the test.

The takeaway - the fact that you got a 780 on the CAT is a great sign, but you should not take it as indicative of what you'll score on the real GMAT beyond the fact that you're performing very well on our practice test. Continue to do your best to identify relative weaknesses in preparation for the real test. The only perfect data remains the real GMAT itself.

I hope that this is helpful to you. Let me know if we can provide any other info or assistance. All of the best, - Andrew
aloksanghavi
 
 

Advice needed

by aloksanghavi Sun Mar 25, 2007 11:28 pm

Hi Andrew,
After scoring so high in the CAT tests i took the GMAT Prep Test2 recently and scored a pathetic 600. I also gave the old Powerprep Test2 and got a meagre 620. Seems like i am completely falling short of time in Verbal and have to guess around 7 questions. My SC accuracy is 95% but RC seems to be a real problem. I am very slow it seems in going through the passage. I was so high in confidence after scoring high in the MGMAT Tests but these gmatprep tests completely shattered my confidence. I really dont know how to improve. It will be great if you can give some advice on how to improve the RC reading speed as well as CR accuracy.

I have only given the CAT tests 1 and 3. I guess i should finish all the 6 tests which would improve my speed also in verbal. Any advice will be greatly appreciated.

Thanks,
Alok
ayang
ManhattanGMAT Staff
 
Posts: 42
Joined: Thu Jul 31, 2003 1:31 pm
 

Maintaining pace

by ayang Mon Mar 26, 2007 11:36 am

Alok,

Your high accuracy in Sentence Correction is very promising. And it sounds like you're on the border of a strong performance.

The crux of the problem in your other tests is, in my opinion, running out of time and having to guess on the last 7 verbal questions. That will be enough to severely hamper most anyone's score. You are essentially assuring yourself of 5 or 6 mistakes at the end of the test that way, with some of those questions representing 'easier' questions that more adversely affect your final score.

A better approach would be, in my estimation, to accept slightly lower confidence and certainty on earlier RC questions. This may include moving off of a question quickly after you have it down to 2 answer choices instead of spending more time reviewing the passage and confirming the answer. It may also mean cutting short your reading and sketching time, even though this may mean that you don't understand the passage as well.

If you force yourself to maintain pace during Reading Comprehension, you may get a couple more wrong answers in the middle of the test than you would have if you had spent extra time. However, this would be more than made up at the end of the test, as you'd likely get 4 out of the last 7 correct, with no 'easy' questions wrong.

In sum, the surest way to bring your score down is to run out of time. You should continue to practice to ensure that you finish on time. If you do this, you will likely find your score to be substantially higher than the 'low' result you received on the GMAT Powerprep tests.

I hope that this is helpful. Let me know if we can provide anything else. - Andrew
aloksanghavi
 
 

by aloksanghavi Mon Mar 26, 2007 12:09 pm

Andrew,
Thanks for your reply. During the middle of the test in the verbal, I see that i am really falling short of time(mainly due to spending lots of time in RC earlier in the test) and so what i do is just guess 3-4 questions RC (1 passage) in the middle of the test and couple of CR questions. This way i ensure that i do complete answering all the questions. THats what i meant by just guessing around 7 questions. I have seen that at the end there are some easy SC questions which i dont want to miss and so I do this.

I think you are right, and the key lies in going through a RC faster rather than spending lot of time over answer choices in a RC earlier in the test. Earlier in the test, it feels you have ample time and want to get everything right. I guess thats my problem.

I will take more timed Verbal tests (remaining MGMAT CAT Tests 4,5,6 ) and see if things improve.

Thanks for all your help. I will keep you posted of any positive developments:))

One more thing, do you think its better to take the test date after i start getting really good score in the GMAT Prep? I live in Philadelphia and virtually i can get the date for the next day.

Alok
ayang
ManhattanGMAT Staff
 
Posts: 42
Joined: Thu Jul 31, 2003 1:31 pm
 

Test date

by ayang Mon Mar 26, 2007 12:28 pm

Alok,

As it seems that you have ample time before 1st round applications, I would agree that you should wait until your comfort level and confidence are high, and that would include doing well on a GMAT Prep test. It's important that you're feeling confident, prepared, and well-rested going in.

Keep us posted on how you do! :)

- Andrew
autodidact
 
 

same situation as Alok on Manhattan CATs

by autodidact Tue Apr 03, 2007 12:19 am

I've gotten really high scores on the two Manhattan CATs I've taken (760 - V-51, M-46, 750 - V-51, M-45). I've been reading the great explanations and doing problems over that I found difficult. According to some of the instructors on this forum, there is a 60 point standard deviation between the Manhattan CATs and real test. I'm hoping that's true. considering I didn't get these scores on the first GMATPrep CAT I took in January (680), I'm a bit concerned. Of course, I think it's a matter of nerves just as much as everything else.
myt
 
 

by myt Tue Sep 02, 2008 12:53 pm

Hi Andrew ,


I know that this is a pretty old post. I am just curious to know if MGMAT has revamped the algorithm recently. I am asking this because you mentioned in one of your above posts that MGMAT was considering the adjustment.

Thanks
StaceyKoprince
ManhattanGMAT Staff
 
Posts: 9360
Joined: Wed Oct 19, 2005 9:05 am
Location: Montreal
 

by StaceyKoprince Wed Sep 03, 2008 5:03 pm

We did make an adjustment to the algorithm not long after these posts - I think in May of 2007. At this point, our SD is around 50 points and the test does not skew high or low on a significant basis - we're able to keep it consistently within +/- 5 points. We recheck the data about every 2 months and make minor adjustments as necessary to maintain the range so that it neither undershoots nor overshoots in general.
Stacey Koprince
Instructor
Director, Content & Curriculum
ManhattanPrep