First, let me say I am a real GMAT test taker. I do not teach for any company and while I used to teach and tutor, I have never taught not tutored for the GMAT. Therefore, everything here is what I actually did. Also, you may be wondering why I put time into the IR section. I won't be applying until the fall of 2013, but only had time to take the GMAT now. Therefore, I have to expect that schools will be looking more closely at IR scores then than they are now.
As noted above, I did not do well in the IR section when I first began. Therefore, I took to analyzing and redoing all problems (correct and incorrect) until I could pick out all the mistakes I was making. As with any studying, this is the most important step, and I took it seriously. However, instead of listing the mistakes I made, I've listed what I did to correct them so that you can see what I found to be most important in my studying for and taking the exam.
Of course, as many people smarter than I have said, doing well in quant and verbal is the first step to doing well in the IR section.
What I learned, in list form:
- Read the captions! They almost always contain data or conversions that you need.
- Optional (but I did this, even on the exam): Take short notes on the multi-page questions (such as a chain of emails). I found that since they tend to illustrate differences, either between processes or opinions, taking notes on this meant I got all the information I needed first time around. It always saved time in the long run.
- After carefully reading the question, formulate a way to solve the question with the data given. If math is needed, write down the formula, at least while you're learning to do IR. Do this before actually trying to answer the question or you'll be lost in your sea of data. As an example, I read medical journals. When I need to answer a question, I don't read an entire article (especially because I usually read more than one to form a consensus). Instead, I figure out what I need to answer the question and where it will most likely be located. Then I attack the articles. Once I smartened up, I did the same for IR.
- Apply this to solve the problem. If it involves math, get used to using the calculator, as you will need it often due to some nasty numbers and answer choices being too close to each other to do the math by hand or estimation in the amount of time you have.
- On the other hand, don't become reliant on the calculator. There is still a minority of number problems that can be done faster without it.
- Check your answer. Does it make sense? When using a calculator, it's very easy to get lost in the keys. We all know that 10*10 does not equal 1000, but when you do it quickly on a calculator it's much easier to overlook this than when you do it by hand. What about 9.97*9.85? Simply because the numbers are worse looking, it's much easier to overlook an answer such as 982 when you're punching keys.
- In multi-part questions, you will often use data that you calculated to solve one part in the other parts (such as an average number). Or maybe all the parts have a similar thread of reasoning. Whatever you do, do not treat each part of a multi-part question as a new question as you would in the quant section, because they often aren't.
- Timing is crucial, but not a problem if you practice the above regularly and become efficient at applying it. Therefore, you must review every practice question you do after finishing a set. This will help you to see what you are consistently doing correctly, incorrectly, efficiently, and inefficiently. Redo any incorrect problems to make sure that you can do them in a good amount of time.
- Official Guide 13th ed.: It has 50 questions included on an easy to navigate website. They're extremely similar in quality and format to the ones seen on the real GMAT, which is to be expected. I found them to be more than enough practice, and was only able to finish half. However, they don't come with a timer. If you have an older guide, you are no longer able to purchase just the IR questions from GMAC. To access them, you must purchase the 13th edition.
- GMATPrep: This has 15 IR questions for free, plus the 12 questions in the practice exam. These were also extremely similar in style and difficulty to those seen on the real GMAT. Note that the GMAC has chosen to use the same 12 questions for both practice tests. According to their website it's not a bug, but just the way it is. Fantastic. Also, you can purchase an addition number of questions from them but I don't know if they overlap with the 50 OG 13 questions.
- MBA.com: On the IR Question Formats page, you'll find 19 problems for demonstration purposes that work well as practice problems, but with a non-functional calculator. This is probably a good place to start. (As I will note again below, the actual test uses one almost exactly like the basic Windows calculator so you can just use that.)
- MGMAT IR: This was by far the hardest of all the study materials. The IR book itself isn't any more useful than the MBA.com website, in my opinion. However, it comes with an online problem bank that, while evident a lot of work went into them, had some minor issues. First, the problem banks don't tell you how many questions each has until you start answering and they don't all have the same number of questions. Therefore, you can't really set a time limit for the sections unless you start one, look at the number of questions, finish it without answering questions, and then starting again. It's annoying, but could be fixed easily by simply putting it on the website or the time limit screen (where the instructions are now outdated). I didn't finish all the MGMAT sets because I felt they weren't better than the ones provided by the GMAC. And more importantly, I felt they probably weren't representative as they didn't seem to match the OG 13 IR very well in style or difficulty. I realized later that they didn't match GMATPrep or the real GMAT that well either.
- MGMAT Practice Tests IR: As with their online banks, their practice tests show that a lot of work went into them. However, they were also in the same style and at the same difficulty level of their online banks, which means they weren't completely representative of the real deal. Nonetheless, there's something to be said for becoming efficient at problems that are harder on average than what you should expect to see. Also note that the calculator is different and more difficult to use from the one you will use on test day.
- The calculator was better than the ones used in GMATPrep and OG 13, and much better than the MGMAT one. If you have Windows, open the calculator and make sure it's set to "standard" mode. This is almost exactly like the one on my exam in look, feel, and features. Unlike some of the practice ones I used, you can click answer choices while the calculator is open. It also worked well with the number pad (as long as you switch/click focus to the calculator) which let me do more calculations in less time. The speed afforded by a number pad is incredible, so if you aren't used to using one, I suggest you get used to it.
- The IR section was similar to the questions in GMATPrep and OG 13. This was great and I felt "settled" in right away.
- If writing is not your thing, then having the AWA right before IR might be a problem for you. As I enjoy writing and arguing positions, I felt pretty energized by the time I got to IR, but I know this isn't the same for everyone. Therefore, I suggest that when you take practice exams, you also write the AWA essay, which I know many people don't normally do.
- I didn't get any questions with this sort of chart. Thank you GMAC for being nice to me. I can't stand those.