Is my preparation complete without the OG

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by Adam@Knewton » Fri Feb 04, 2011 12:58 pm
Ikonik wrote:Hi,
I've been studying from Kaplan books, along with the Official Guide Verbal Review.
But the big question on my mind is - despite having these books, do I still need the Official Guide to complete my preparation?
I know many students, when I used to work at Kaplan, who never went much beyond the Kaplan materials and still ended up doing very well. However, I think everyone here will argue that the more resources, and the more different resources, you look at before test day, the better. I'm not sure there's any such thing as a "complete" preparation, but the OG is an easy investment to make that can pay great dividends.

One danger of studying from only Kaplan materials, or from the materials of any test-prep company alone, is that you might get too used to the Kaplan wording of things and not really garner the one true skill you need for test day: the ability to decipher what a question means regardless of how strangely it's phrased (and they will phrase things strangely on test day!). This is of particular concern to non-native English speakers who rely on memorizing certain buzzwords to tell them what's being tested, in both Quant and Verbal questions. Looking at the OG questions will help you see not only how the GMAT words things, but also how well you respond to slightly different phrasings of the same concepts.

This being said, I'm not an advocate of the OG as an essential piece of preparation, simply because I don't think it's the best resource of GMAT material. In making it, the GMAC clearly held back on most of their more difficult questions, and too many students assume, I think inaccurately, that only the Officially Released questions are truly reliable as GMAT-like.

Short answer: Yes, you should get it and use it, but no, it's not as "necessary" as some may claim, in my opinion.
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by David@VeritasPrep » Sun Feb 06, 2011 3:16 pm
There are various opinions on this and mine is "Yes. You do need the Official Guide." I mean, they are offering to sell you 800 questions that have been on the actual GMAT for what, $36 (less than $25 at Amazon). This is too good to pass up.

Here are some reasons why you need to do official questions:

1) Official GMAT questions cost $2500 each to write (according to Business Week). That makes these the best edited questions available. You have the Verbal Review, which will help you on the verbal side of things to understand what an official question is like. This is very important as official questions are tighter and better written than unofficial questions. This is what is so difficult, for example, for critical reasoning - the question has to be very tricky as it is presented, but there can be only one correct answer and when that answer is explained there can be no doubt. That is where the $2500 goes! It is tough to write questions that well - to fool people and yet to be absolutely fair.

2) There are two types of difficulty on the Quantitative one of these is covered best in OG. The first type of difficulty is the upfront difficulty the obvious difficulty that unofficial questions do well. The circle inside of a triangle inside of a square sort of thing. These are actually easy to construct and unofficial sources are good at this. But the second kind of difficulty, the "sneaky difficulty" is done best in official questions. This type of difficulty is where they funnel you toward the wrong answer. It is remarkable how those who have chosen the wrong answer are often more confident than those who have the correct answer.

Anyway, I would just personally not want to sit for the test without having maximized my use of the OG 12th edition (as well as other resources of course).
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by Ikonik » Sun Feb 06, 2011 11:20 pm
I agree.
I remember I finished the section on CR from the OG Verbal Review, then moved to Kaplan 800 book for CR. I was surprised to see that my accuracy of about 80 to 90 percent on the OG Verbal, went down drastically on the Kaplan. It wasn't the difficulty level that baffaled me, but more likely the phrasing of the catch sentences. I was in the OG - VR flow, and the other book just had a different way of phrasing its sentences, but objectively I couldn't pin-point the difference.
Later my score on the Kaplan improved, but now I wonder if it'll happen again when I move back to the OG questions?
Anyway, I'll now pick up the OG 12!

Here's another doubt, if I finish the two free test that come free with the official Gmat software, can I reinstall the software to get another shot at it?
Thanks

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by David@VeritasPrep » Mon Feb 07, 2011 5:36 am
You actually do not need to reinstall the test to take it a second time, even a third time. Simply restart the test.

You will find that questions are repeated in each section verbal and quant. It should not be that many. A few per section. This will happen whether you reinstall it or not.

It is no problem if you get 4 or 5 repeats. Go ahead and answer them correctly, however you need to let the clock run so that you do not answer these questions in 10 seconds! In fact, go ahead and go through the process of solving or answering the problem/ question. This way you are preserving the time challenge.

With the third attempt you will see more repeats but usually not too many and it is worth it to get to use the official interface and the official questions as often as possible.


Oh and one note from above. The fact that I quoted above (Business Week article discussing a lawsuit filed by GMAC in which they reveal that questions appearing on the GMAT cost $2500 each to write) actually supports something that Adam said above about holding back the best questions that they have to keep using them on the official GMAT. This is something that Brian Galvin the Director of Academic Programs at Veritas pointed out to me years ago and it is one of the reasons that supplemental materials are helpful in adding difficulty to your studies and one reason why we never say, for example in critical reasoning - I have not seen that question in the OG so it is not valid.
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by Ikonik » Mon Feb 07, 2011 5:59 am
Hmm... that makes sense! (an incorrect sentence from the SC point of view - what does 'that' refer to) :)
Well, I mean both the points you mentioned - about the GMAT test, and about the reference material.
Thanks.

P.S. I posted this https://www.beatthegmat.com/really-baffl ... 75229.html , I'll post the answer tomorrow (to avoid spoiler for those who wish to attempt it). I'd like it if you could visit the link tomorrow and probably share your views on the answer.

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by Brian@VeritasPrep » Mon Feb 07, 2011 10:08 am
Great discussion, guys, and as David mentioned I fully agree with him and with Adam about the idea that GMAC will tend to hold back its hardest questions. It's probably not all that relevant to the way that you study, but since the discussion is out there I figure I'll chime in with a few reasons for that.

1) Like David says, these questions cost $2500 on average to create, and the really-tough ones have to cost more; having created some questions myself, I know that the harder you make a question the more eyes you need to get on it to make sure that the trap answer is "devilishly clever but 100% incorrect" and not merely "kind of defensible and probably a second correct answer". The hardest questions are the toughest to write, so GMAC really needs to make sure it gets a high ROI on those.

2) There are exponentially more "average" questions out there than there are incredibly hard questions. The GMAT scores fall along a normal-distribution bell curve, and accordingly more people score in the middle bands (400-600) than score on the extremes. Add in the adaptive scoring factor and GMAC has to create a lot more 600-level questions than 700-level questions, since most examinees will require scores in that 400-600 band. So there just aren't as many hard questions to retire.

3) The difficulty on the GMAT has to "move" and evolve - particularly with the advent of sites like Beat The GMAT (tip of the hat to Eric, David, and Bea), what is "hard" becomes easier fairly quickly nowadays...people get a sense of what they need to study for. 6 years ago, Permutations/Combinations was the elite level of GMAT quant...people couldn't figure it out when they saw it for the first time. But within a few months, internet forums started discussing it, companies built lessons around it, and the difficulty was eroded a pretty good amount. Once a hard question type gets out in the public domain it loses a percentage of its difficulty, so GMAC really needs to protect its hard questions and also to stay ahead of the curve.

4) GMAC itself will admit that the Official Guide series is much more a "collection of retired GMAT problems from which to study" than a "blueprint for what the test looks like today". Its stated mission is not to be proportionally representative of the concepts you'll see or of difficulty levels overall, so GMAC isn't putting much effort into doing so. If anything, the official mba.com practice tests, because they have to include difficulty-level based questions for their scoring algorithm, are the study tools to follow to find out where the difficulty may come from.

So, like David says, the OG is a great study tool at an attractive price point, so I'd certainly endorse it as a powerful study tool, but I'm also quite leery of the arguments that "I can do all the questions in the OG so I will score 700+" or "The OG doesn't have a question like that so you won't see it on the test." Combine the OG with some imagination - train yourself to Think Like the Testmaker and find other ways they can test those concepts or add twists to those questions along the same lines - and then you ought to be in great shape.
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by Ikonik » Mon Feb 07, 2011 10:58 pm
Brian@VeritasPrep wrote:
3) The difficulty on the GMAT has to "move" and evolve - particularly with the advent of sites like Beat The GMAT (tip of the hat to Eric, David, and Bea), what is "hard" becomes easier fairly quickly nowadays...people get a sense of what they need to study for. 6 years ago, Permutations/Combinations was the elite level of GMAT quant...people couldn't figure it out when they saw it for the first time. But within a few months, internet forums started discussing it, companies built lessons around it, and the difficulty was eroded a pretty good amount. Once a hard question type gets out in the public domain it loses a percentage of its difficulty, so GMAC really needs to protect its hard questions and also to stay ahead of the curve.
That made a lot of sense to me :)
But you mentioned that we ought to put ourselves in the examiners shoes, think of what could be his/her next target in terms of the question type, because
a. GMAT is evolving
b. difficulty of a question is inversely proportional to its life post release
So, to do this, I'd like to know if there is a curriculum of any sort for the GMAT, wherein I could explore the tougher areas in the curriculum. Saying number theory is by itself includes even the Fermat's Last Theorem, which certainly cannot be touched by the GMAT (my guess, hope and prayer :?)!

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by Brian@VeritasPrep » Tue Feb 08, 2011 12:28 pm
Glad it got you thinking, Ikonik - and great question. Yeah, it's definitely not a case of your needing to predict new content that the GMAT might test (because it won't add anything completely out of nowhere), but more about your wondering how a concept could be tweaked differently. So, for example, you might encounter a problem that would ask you the probability of getting the sequence Heads-Heads-Tails on three flips of a coin. When you see that question, you should ask yourself how they could make the question harder, such as by asking for just getting the results "two heads and a tails" without the order mattering. That would give you multiple sequences to the same outcome, and require you to think of them all (H-H-T, H-T-H, T-H-H). In this way, you're anticipating how the topic (Probability) can be made more difficult.

Maybe a better example, since you mentioned number properties, is a question like this:

What is the units digit of 7^10 - 5^9?

A) 2
B) 4
C) 6
D) 8
E) 0

Here, you'd follow the pattern of powers of 7, which elicits units digits of 7-9-3-1, and determine that the first number would give end in 9 and the second will always end in 5, so you'd have a units digit of 4, or answer choice B.

How could they make this pretty-tough question damn near impossible? What if they asked:

What is the units digit of 7^10 - 5^19?

A) 2
B) 4
C) 6
D) 8
E) 0

Here, you'd perform the same methodology, but you have to remember this: the second number is larger, so the answer will be a negative number, so instead of calculating larger-minus-smaller:

9 - 5 = 4

You'll have to calculate smaller-minus-larger, like:

9 - 15 = -6

So here the answer would be C, because they add that step to keep you on balance...you have to consider the relative sizes of the two numbers being subtracted. I do this demo with my classes all the time - if you can predict the traps that the GMAT might lay for you, you're well ahead of the game and can avoid them.
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