Differences between scores from official mock and others

Question

Hi all,

I have been preparing for GMAT for around a month now. For the past few weeks, I have been practicing solely on OG questions after reading many posts from this forum. Now I have completed around 70% of OG questions. I also took 3 official mocks and I was pretty satisfied with the results:
- Mock 1: 640 (first attempt without any prep - spent a lot of time trying to understand the GMAT question types), 750 (second attempt)
- Mock 2: 740
- Mock 3: 730

Since I don't want to use up all OG questions so soon, I started attempting questions from GMATClub and other third-party prep companies a few days ago. I realized my scores were significantly lower when answering non-OG questions. Now it makes me really worried about my performances - should I trust my OG scores (and use OG questions exclusively) or is there anything I am missing? I also found that the question styles of non-OG questions (even from reputable sources) very weird, as compared to OG questions. Not sure if it is just my perception or not. Any thoughts?

globaldesi · Answer

OG scores are of course the most reliable source but given that you should actually look up for your areas of practise where you need improvement.
Quite a possibility that you have seen those question before so be cautious about that

AndrewN · Answer

Hello,  graceltw . Place stock in your performance on official questions, and do not be quick to exhaust your resources of such questions. There is indeed a difference in the feel of third-party questions, and the reason is simple: GMAC™ does not license official questions, so third-party companies can only get so close to mimicking official questions (or else risk a lawsuit). Verbal in particular can look quite different from one source to another. My recommendations for materials to practice are as follows:

Verbal :
1) OG/Verbal Review
2) GRE® (for RC or CR)
3) LSAT (for certain types of CR)

Quant :
1) OG/Quant Review
2) GMAT Club (for those shooting for Q49+ especially)
3) Manhattan Prep

Of course, 1.5) on both lists could include the paid prep packs you can get through mba.com, since you can practice many more official questions that are not found in the other sources, but I like to make my recommendations with a low budget in mind. You may also consider online learning modules if you prefer to acquire test-specific knowledge that way.

Finally, to speak to the discrepancy you are seeing between official practice scores and third-party scores, that is quite common. I know of at least two people who have earned a 50 in Quant on the actual exam who earned a 44 (both of them) on their GMAT Club mocks. I have also read debriefs from 750+ scorers who reported Manhattan Prep mocks in the 600s. Take third-party material with a grain of salt. Learn what you can from it, but make sure you center your studies on official material and apply any knowledge you may gain from third-party material to the real stuff.

Good luck with your studies.

- Andrew

graceltw · Answer

Thank you very much! I am struggling particularly with the third-party verbal materials. Maybe I should just stick with the official prep for verbal then!

For quant, I found that I need more practices with particular topics (i.e., number properties, remainders, etc.). When doing official mock exams, I got pretty decent scores as I did very well in other topics, so I thought I master Quant but actually I did not! I will use GMATClub questions for the above topics then. Thanks again!

ScottTargetTestPrep · Answer

Hi graceltw,

Things seem to be going pretty well with your practice exams. Since your post have you taken any other practice exams? When is your actual GMAT?

Differences between scores from official mock and others

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