Good discussion! I agree with the majority here that these days most GMAT studiers would be better off sticking to a steady diet of official GMAT materials throughout their entire preparation. That goes for regular skill building type HW and for practice tests. Why not use third party questions and practice tests? Because you have a better option! There’s just no contest. I've worked with plenty of people who've achieved whopping GMAT scores (740s, 750s, 760s. 770s, and 780s) focusing on 95% Official GMAT questions and practice tests. Can you do well with third party material? I'm sure you can. But in my mind it's just not the best thing for most people.
It is true that there are some Quant content areas that are a little under-represented in the official GMAT materials. But the reality is, unless you’re hiring someone who has a really good understanding of what needs to be supplemented (or are willing to put in the effort yourself to figure it out. Not sure if this is possible in a reasonable amount of time.) then you really are better off just sticking to the official stuff. And, even if you are going to try to supplement with some third party questions, you don’t need that many. Depending on the student, I use about 60-70 questions (that I’ve written to cover some gaps) outside of the official GMAT quant. That’s it. Besides that it’s all Official GMAT. And, don’t hire me (or anyone else) based on these extra materials. They help but are just a bonus. You can have an amazingly thorough Quant prep with
only the Official GMAT materials.
Many test prep companies stress analytics. But, in my mind, unless analytics are tied to real GMAT questions and in the case of a CAT, the real scoring/question selection algorithm, the stats aren’t terribly helpful. In fact, I’ve found that students get distracted by the analytics. They start over-focusing on certain content areas on which they think they are weak. But are the students actually weak in those areas or:
1. Is it that the test prep company has written tough questions in that content area.
2. Is it something else about the question (not the main topic) that is tricky and got the student tripped up.
Even if it is so that a student is weak in a specific area, obsessing on that may not lead to a better outcome. That type of narrow scope can shift the focus away from what the GMAT is about: critical thinking! Yes, you do need to have basic fundamentals in place. But, I’d bet that you could not know a thing about probability and still get a 700+. Once you’ve got the meat and potatoes in place, you’re so much better off taking a holistic view of your studying. Overdoing the analytics, especially ones based on third party questions, algorithms, and content distribution can take away from that big picture view and really distort the focus of a GMAT prep.
Would it be nice to see a per question timing breakdown on the official practice tests? Yes! Is that enough of a reason to use a third party CAT? NO! The first thing that comes to my mind is that a student could have timing issues on the third party CAT and not on the Official one. Or vice versa. After all, the tests are not the same. And, at least in my experience, it’s not difficult to determine in the aftermath if a student had a timing issue on a practice test. If there were two minutes left for the last ten questions, guess what, there was a timing problem! There are other types of timing issues (1. getting anxious about time in the middle, rushing, and then having leftover 2. Rushing the first 10...) but usually the student can relate that information. Fixing the issue can take some subtlety but diagnosing timing issues generally isn’t rocket science:)
When might you use non-official GMAT materials (on the Quant side)?
1. You’ve been studying for such a long period of time that you have done every official question 5 times:) At that point you will probably benefit from some third party questions. You can run out of questions (probably the only place I disagree with Brian). It takes a really long time (this will not happen to a vast majority of people) but it can happen. Also, many of the thousands of Official Questions are easy. So for people already scoring well, there is a much smaller pool of worthwhile practice.
2. If you are really gunning for a 51 on the Quant. Not a 45, 46, 47, 48... a 51. You might benefit from doing some of the really tough GMAT club quant. But that’s after you’re already scoring in the high 40’s.
3. You’re starting with a Quant score below 30 or so. In this case you may want to start out with some really basic Quant. You don’t need to use official GMAT questions to build the very basic fundamentals. You could work through some Khan academy Quant or some old GRE quant or any number of third party “learn test prep quant” solution. But Khan is free and certainly has all you need for the basics.
For verbal, things are a bit different. Still, do not use any third party GMAT questions! Really. Stay away. But, I would consider using LSAT logical reasoning to train your GMAT critical reasoning. If you’re scoring in the 20’s then the LSAT stuff wouldn’t be a great place to start. But, if you’re consistently 30+ on the verbal then I would consider tackling a bunch of LSAT logical reasoning.
In terms of materials that have been discussed here I’d just add that I like the GMAT paper tests. They are expensive. Agreed. It would be nice if all nine were available for the cost of a set of three. It would also be nice if GMAC just pulled the unique questions from the paper tests and popped them into a question bank. That would be great. That said, they are still a good source of SC and CR with plenty of tough questions. Yeah, you have to avoid some the questions and tests because they are riddled with questions repeated elsewhere but even given that you are still left with an excellent chunk of verbal practice. The Quant I would completely avoid. Are the GPTs the lowest rung of official practice? Well, probably close, but I would put GMAT Write and the IR Prep Tool there at the bottom:)
Great discussion everyone - happy studies!
A.