Verbal Correction Rate and Good Score

[snuman]

I am able to solve correctly 60% to 70% of the Verbal Questions contained in OG-10/11 and Official Verbal Review Guide, within avergae GMAT time. My correction rate has gone up to 80%-90% but with some extra time. How much should i worry about my 60%-70% correction rate that's within time? And with this rate in actual GMAT how much should i be able to score in verbal?

Nauman

[VP_Jim]

It's tough to say how well you would do with 70% correct because your score is based not only on how many questions you get correct, but at what point during the test you get your incorrect questions (i.e., earlier incorrect questions will hurt more than later ones) and the difficulty of the questions you get right (harder questions are worth more points).

I would say that if you're getting practically all of the easier and medium questions right and half (or so) of the harder questions right, you're in pretty good shape.

The OG goes in approximate order of difficulty within each section, so if most of your incorrect questions are towards the end, you're doing pretty well.

I'd also encourage you to take a practice exam to get a more concrete evaluation of your score.

[reza]

It really depends on your target score...

For example, if you need around 650 and your math is great, then you will be ok. Make sure you do great in Math no matter what!

But if you need higher scores, then you should break down the "verbal" section into bits and pieces and see really what are your weaknesses and strengths. For example, I knew that I suck at the 3rd reading comprehension and my correct rate was 60%. So what I did during the real test was to read it very quickly maybe in a minute or two and then guessed the answers knowing that I would get probably 40% right which is not much worse than 60% for one single reading comprehension and moved on the next questions. That strategy spared me 10 minutes extra to get right what I am good at. The end result was a 700+ score.

If you want you can use this spread sheet to monitor and design your own strategy for the studying and taking test.

https://www.gmat760.com/Gymat/Material/Swic.xls

Also, if you want to maximize your score, you should familiarize yourself with CAT a bit. Sometimes it is better to get the answer wrong so the next question would be easier. But you should really know how CAT works...
Check this out....

https://www.gmat760.com/Book/Ch5_CAT.aspx


I hope I was helpful

[VP_Jim]

Just so we're all clear, it is NOT a good idea to intentionally get a question wrong. I think the author of that site was trying to say that sometimes it's best to guess and move on if you're stuck. Never select the wrong answer when you know the correct answer.

[reza]

Absolutely

It will be stupid if you know the right answer and yet pick the wrong one!

Thanks for clarification

[snuman]

Thanks guys.

The thing that alerts me again is the thing that early questions are important. I have read here and on some other website (e.g manhattangmat.com) that it’s just a myth. But here you guys are emphasizing it given the nature of the CAT software. So what number of initial questions you would recommend to focus on as some say first 10 and others say first 8 or even some go on to say first 15?

Here i would also like to add this page by Lawrence M. Rudner, VP, GMAC: https://edres.org/scripts/cat/catdemo.htm, which really confirms this myth that first questions are important. Need your comment on it also.

Nauman

[reza]

Hi.

Basically any CAT-based test is like playing chess or backgammon. the difficulty of the next question depends on your current answer.

Also, beware of those experimental questions, whether you get them right or wrong, have no effect on your final score.

Again depending on the score you need to get into your desired MBA school, your strategy will be different. But one thing is for sure that you have to set the base score as high as you can.

It usually takes CAT, 15 questions to set a base score for you but to be safe, try your best for the first 20 questions. Keep in mind that the probability of having an experimental question in the first 10 is almost none.

Another thing is that most students make a fundamental mistake and that is they try to allocate their time evenly among all questions. this is wrong. Instead, you should allocate more time to the first 20 questions. Once you set a very high base score, no one can take that away from you.

I hope it's clear.

Cheers,

Reza Sabernia

[nadontheway]

Reza, in you blog you said:

"In GMAT, The initial 20 questions determine what is called the base score. It means after the first 20 questions, the system has determined the range that your final score should fall within them. Your final score will be a number within the range of the base score and determined by how well you do with the rest of the questions."

I suggest you to check those links to see that what you said is not completly true.
The following replies come from Gmat tutors:
https://www.manhattangmat.com/forums/are ... t4494.html

https://www.manhattangmat.com/forums/mgmat-t407.html

https://www.beatthegmat.com/some-reflect ... t8396.html

You can find more info on this topic if you search.

Now, I am basing my study plan on the time management suggested by the tutors. I noticed that I am running out of time and have to guess at the end of each section. I used to make between 4 and 8 incorrect answers in a row, which decrease my score (based on what I understood from gmat tutors'posts). Hence, I'll focus less on the first questions and try to balance adequately the time for all questions.

Best,

[reza]

Hi,

Thank you for your attention to my blog.

I agree with you that what I said is a simplistic view of the reality.
In the third link that you posted, the author mentioned how a patchy performance might delay CAT to determine your base score which is very accurate.

As a computer science major specialized in A.I., I have studied CAT's algorithm as a part of one of my course projects; It is a probabilistic algorithm and initially it uses psudoguessing parameters to select the questions; hence, even the creator of CAT cannot determine the final outcome if someone becomes an outlier with weird performance. there are many more aspects of it that will fall out of the interest of the readers.

However, as I understood, the other posts in those links were refering to the prep GMAT exams, not the real test. Was the prep GMAT test using CAT also? You know that it is very expensive to make a solid CAT. Initially, You need to give 1000 of people the same experiential questions and then they must take a pre-scored test. only then the developers of CAT can determine what the seeding scores should be for each experiential question and that willl be the initial pool. Only then, you can start doing the proper test and throw experiential questions. it will ultimately becomes a self-relient and "fair" test.

Another thing I want to clarify. I NEVER said that you should leave out te last questions. But if you were to choose which ones you want to get right, which ones would you choose? the first 10 or the last 10? I would go with the first 10 questions.

Secondly, in the last 20 or so questions, you have roghtly 20% to 25% chance of having an experiential question. So if you see it gonna take alot of time, why not guess and move on. it might be an experiential question which has no impact on your final score. At the end of the day, to get a high score you do not need to get everything right. I got Q51/V42 and ended up with 760. During the exam, whenever I thought the question might take up a lot of time, I would use POE to eliminate the obvious ones and would make a guess among the remaining.

Finally, my goal in my website is explain my own strategy and I've emphasized that everyone should tailor his own. What worked for me only worked for me because I had less than two months to study for GMAT - primairly only weekends since I worked fulltime and studies part-time. - and as you can guess my English is far from perfect. I knew I couldn't beat it unless I picked the battles myself. I created SWIC and through that I realized SC is not my battle! Also, the 3rd RC was a killer and would cause timing problem. So, I tried to spend as little time as possible in these two areas in the verbal section.



I appreciate your feedbacks about my posts and blogs. The last thing I want is to mislead the readers. I created that website just to share my experience and tools - as you can see there is no commercial links or even google ads.


Lookforward hearing from you,

Reza Sabernia

[Ian Stewart]

Yes, the information Reza gives above about the GMAT scoring algorithm is not at all accurate. There is no 'turning point' in the test where the algorithm switches from finding a 'base score' to 'finetuning' your score. At the end of the test, your performance on *all* questions contributes to the determination of your overall score- based on the difficulty level of the questions answered correctly and incorrectly, the algorithm tries to find the difficulty level at which you were answering 60% correctly. The score calculation itself makes no distinction between early questions and late questions. The algorithm is based on IRT principles that are widely published.

Nor is it true that experimental questions are saved for later in the test. A GMAC research report discusses the use of experimental questions- experimental questions are organized into pools, and when you start your test, one pool of experimental questions is chosen at random to be included in your exam. These experimental questions are then inserted randomly into your test.

Stacey Koprince has, on many occasions, discussed the scoring algorithm in detail on this forum, and all of her advice and information about it is excellent. In particular, any long string of incorrect answers is seriously damaging to your score; spending excess time at the beginning of a test makes such a string more likely at the end, since you will likely need to guess at many questions, and this can result in a severe score penalty. If you spend so long on the first 20 questions that you need to guess at many questions at the end, you will likely do considerably worse than if you had adopted a more balanced approach to time management.

[Ian Stewart]

However, as I understood, the other posts in those links were refering to the prep GMAT exams, not the real test. Was the prep GMAT test using CAT also? You know that it is very expensive to make a solid CAT. Initially, You need to give 1000 of people the same experiential questions and then they must take a pre-scored test. only then the developers of CAT can determine what the seeding scores should be for each experiential question and that willl be the initial pool. Only then, you can start doing the proper test and throw experiential questions. it will ultimately becomes a self-relient and "fair" test.

Yes, the questions in GMATPrep are retired GMAT questions. That is, they have already been calibrated, and their difficulty, discrimination and pseudo-guessing parameters are known. Once you have this data for a pool of questions, implementing an IRT-based scoring algorithm is not difficult.

[reza]

Hi Ian,

As I mentioned in the post above, in my website, I tried to simplify CAT which means it is not going to be 100% accurate but I believe that is better than knowing nothing and acting uniformly as if it is a paper-and-pencil test. However, the statement of "not being accurate at all" is not accurate either!

As I repeated a lot in this very thread, I NEVER said the last questions are not important at all and you should leave them out. But I would never sacrifice my first 10-20 questions for those last ones. Why?

What you said about the string of wrong answers is correct in an exam with unlimited number of questions which the termination point comes when the system is sure about your ability. But in the real test, you have a limited number of questions to answer. So if you start off with wrong answers, let's say due to nervousness, you may never have the chance to prove your ability only because the number of questions are limited and the section will end long before you can come back.
The opposite is true. Imagine, you get lucky and for some reasons you know the answers of the first 40 questions, how many question should you do wrong for the system to know that you were not as smart as it estimated initially? Another 20? Since there are about 50 questions in each section, the system will not have the opportunity to find out your real ability. I do not DENY that it will punish you for the wrong answers as you can see in the graph in my website, you can lower your score with bad performance. But the punishment does not justify why someone should blow the first questions to get the last ones right!

Finally, I NEVER said that the experimental questions will ALWAYS come at the end. but it is more likely it will not be among the first 10 questions. why? a simple logic!

the system does not have a predefined number of experimental questions to give. You may get 5 or 15 or none. it depends on your performance. If you are too volatile, you might get fewer since the system needs to ask more of real questions to estimate your ability. In fact, it has no value to give an experimental question to someone that even the system does not know how good he is! Right?

Now, considering that there is very limited number of questions to ask, and you have no idea how good the examinee is, would you give all the experimental questions early in the exam? what if you need to ask more of the real stuff due to patchy performance? the system would not give away the "precious" limited questions unless it is sure it can afford it.


I agree with you that a uniform performance yields the best result. No doubt about it.

I believe the disagreement between me and you is not about how the test performs or how CAT scores. but it is about how we look at the test as a whole.
You seem to be more confident than me in the regards to different aspects of the test and you can perfrom uniformly well for all the given questions. Your score of 780 speaks for itself.

But for me, considering my level of "proficiency" in English and having very little time to study, I did great with 760. Unlike you, I couldn't perform uniformly well. I had serious timing and stamina problems. So, I picked my battles and modified strategies such as SWOT to serve my needs.

I hope I have been clear in expressing myself.

Thanks for your replies.

Cheers,

Reza

[nadontheway]

Not easy to understand how a CAT works when you are not an expert (I am talking about myself).

Ian confirmed what I've read until now and my plan is based on what tutors said.

Now, Reza, you have another strategy. The one I used to read at the beginning of my studies (also taught by Kaplan). later, I realized that tutors called it a myth.

Stacey Koprince seems to have met the representative of the Gmat CAT and analyzed the academic study on IRT (I have never read it myself).

Except the fact that you studied CATs, how can you justify (with links or articles or any official statements) that the first 10-20 questions are more important than the last 10 (if you have to make sacrifices because of bad timing)?
How can you also justify that the string of wrong answers can damage your score in an exam with unlimited number of questions? Stacey never mentionned this point. She has just said that it is damaging to get a string of wrong answers (mainly at the end of the test because you have no more questions to catch up) but did not specified the unlimited or limited aspect.

I also have serious timing and stamina issues. And I am non native English speaker either. Thus to me, it is crucial tu understand how to allocate the time.

Thank you.

[Ian Stewart]

Hi Ian,

As I mentioned in the post above, in my website, I tried to simplify CAT which means it is not going to be 100% accurate but I believe that is better than knowing nothing and acting uniformly as if it is a paper-and-pencil test. However, the statement of "not being accurate at all" is not accurate either!

As I repeated a lot in this very thread, I NEVER said the last questions are not important at all and you should leave them out. But I would never sacrifice my first 10-20 questions for those last ones. Why?

What you said about the string of wrong answers is correct in an exam with unlimited number of questions which the termination point comes when the system is sure about your ability. But in the real test, you have a limited number of questions to answer. So if you start off with wrong answers, let's say due to nervousness, you may never have the chance to prove your ability only because the number of questions are limited and the section will end long before you can come back.
The opposite is true. Imagine, you get lucky and for some reasons you know the answers of the first 40 questions, how many question should you do wrong for the system to know that you were not as smart as it estimated initially? Another 20? Since there are about 50 questions in each section, the system will not have the opportunity to find out your real ability. I do not DENY that it will punish you for the wrong answers as you can see in the graph in my website, you can lower your score with bad performance. But the punishment does not justify why someone should blow the first questions to get the last ones right!

Finally, I NEVER said that the experimental questions will ALWAYS come at the end. but it is more likely it will not be among the first 10 questions. why? a simple logic!

the system does not have a predefined number of experimental questions to give. You may get 5 or 15 or none. it depends on your performance. If you are too volatile, you might get fewer since the system needs to ask more of real questions to estimate your ability. In fact, it has no value to give an experimental question to someone that even the system does not know how good he is! Right?

Now, considering that there is very limited number of questions to ask, and you have no idea how good the examinee is, would you give all the experimental questions early in the exam? what if you need to ask more of the real stuff due to patchy performance? the system would not give away the "precious" limited questions unless it is sure it can afford it.

Well, we agree on a few points. CATs are surely different from pen-and-paper tests, and a test-taker should understand going in that the test will continue to get harder until questions are too difficult to answer, no matter what your ability, unless you are a top-level performer. That is, almost everyone will struggle to answer many questions on the test, and this is not a sign that you're doing badly. The goal of the test is to discover the difficulty level at which you answer 60% of questions correctly, so beyond a certain point in the test, it is likely you will answer roughly 40% incorrectly, unless you are at one extreme on the ability scale.

It's also true that the GMAT is not an 'ideal' CAT; ideal CATs are not of fixed length, and terminate when the algorithm's confidence level in your ability exceeds a predetermined value. However, the GMAT has been designed to be sufficiently long that this confidence level will in almost all cases be acceptable, and questions with unsuitable statistical properties (poor discrimination, for example, or extreme difficulty values, whether too high or too low) will be discarded from the question pool to ensure this. If the test wasn't certain to attain this confidence ('information') level, the test would have no validity. The fact that the GMAT is of predetermined length also does mean that earlier questions are slightly more important than later ones; in particular, it means that it barely matters if you need to guess at one or maybe two questions at the end. A long string of wrong answers is especially damaging, however, regardless of whether the test is of predetermined length; this is a consequence of the IRT principles behind the algorithm.

There is published information about how experimental questions function on the exam and you can read about this in GMAC research reports. The number is predefined, and some of the questions will be inserted early in the test. Experimental questions are divided into pools of between 7 and 14 questions each. Each test-taker, before they begin a test, is assigned one pool, and these questions are randomly inserted in the test. Because the test is designed to achieve a certain minimum information level, the experimental questions, logically, can be inserted early in the test, long before the algorithm has determined the test-taker's score, because there will be a sufficient number of appropriate real questions later in the test to determine that score.

[snuman]

Hi All,

I somehow agree wid reza and would like your attention on this CAT simulation link by GMAC, VP: https://edres.org/scripts/cat/catdemo.htm

He has included CAT simulation in this page which shows that if your correction rate is high in the beginning then your final score could be high. But on the other hand if your correction rate is low in the beginning then it’s very difficult to raise your final score.

However, he has also mentioned on this page that: "When the examinee is given a sufficient number of items, the initial estimate of ability should not have a major effect on the final estimate of ability". OG guide also says that computer uses the first 10 questions to get initial estimate of your score.

I guess the real myth is that how much you score drops once you have achieved a high initial estimate by correcting most of the first 10 questions. And that all may depend on time management and guessing strategy, after you have achieved a good grasp of the subject matter.

Nauman