The Next-Gen GMAT: Graphics Interpretation

by on March 26th, 2012

The launch of the Integrated Reasoning (IR) section is getting close! The last administration of the old version of the GMAT will be on 2 June; the next-generation GMAT will launch on 5 June. It’s not too late to study for the old version, but it’s also not too early to start thinking about studying for the next-gen test, including IR.

So let’s talk about one of the four IR question categories: Graphics Interpretation. IR in general is a mix of quant and logical reasoning, so expect to bring your critical reasoning and reading comp skills into play on this section.

Before we dive in, just a note: a new Official Guide (13th edition!) was just published; it has an IR section along with an additional IR resource online (to which you get access if you buy the book). I would guess that most test prep companies will also be releasing their IR study materials next month (we certainly are!).

Try the problem

Let’s try out the question: here it is. Just in case that link changes, you can also click on this link to go to the next-gen GMAT website, and then, about halfway down the page, click on the “Graphics Interpretation” link. We’re going to try the 2nd of the 4 questions.

Note: when you are done, do NOT click the “next” button. Just leave it up on the screen and come back here.

Set your timer for 1.5 minutes and go! (Note: we have an average of 2 minutes and 30 seconds for each IR question in the section, but some question types are more complicated than others. I recommend trying this one for 1.5 to 2 minutes initially, as it is shorter than some of the other question types. Just note that, as you study, you’re going to have to determine your strengths and weaknesses so you can learn to balance your time appropriately.)

That graph is scary.

Yes, it is. I’m with you. Don’t look at the graph first. Read the text below it; that will help orient you to what the graph contains.

The first sentence tells us we have three columns (we can see that ourselves) with a bunch of geologic info. I found the second sentence really confusing and had to read it twice; the “but otherwise” language confused me because all three columns have timeframes to the left, so why is there contrast language there?

I did eventually understand what they were talking about but only after I was done with the problem and read it yet again. Here’s the thing: I still wasn’t sure I fully understood it when I was doing the problem. I just said to myself (after the second reading), okay, each one has its own timeframes. And that’s good enough for now.

The third sentence (and actually the second sentence as well, but I didn’t get this when I was doing the problem)  indicates that the 2nd column is a subset of the first and the 3rd is a subset of the second. The gray shading and dotted lines help make that more clear.

Okay, next I did look up at the graph, but not for very long. What am I going to do, memorize all the numbers and names? :) No way. Moving on to the first question.

The Questions

The Miocene epoch spans closest to _______ of the era of which it is a part.

The “Miocene epoch” – okay, let’s go find that in the graph. Only the third column has a header labeled “epoch,” so look there. Okay, found it… now what does the question say? The Miocene is part of an era. Which one? Oh, I see – the gray shading and dotted lines indicate the Cenozoic era in the middle column.

And I suddenly realize that I’m not quite sure what kind of thing is supposed to go in that blank. I should have looked at the answer choice options. There are three: 3%, 25%, and 85%.

The Miocene epoch spans closest to (3% / 25% / 85%) of the era of which it is a part.

This is making a lot more sense now. The Miocene was what percentage of the Cenozoic? The Cenozoic is that whole third column, so it was about 65 million years. The Miocene isn’t 85% – that’d be way more than half – and it isn’t 3% because that’d be almost nothing. So it must be 25%. Now I’m really glad I looked at the answers – I was able to avoid actual calculations!

(If you do want to check the calculation, estimate the length of time for the Miocene. That was about 5 million to about 23 million, or about 18 million years. 18 million / 65 million = 28%, roughly.)

Here’s the second question:

According to the diagram the beginning of the _____________ marks the onset of a new eon, era, and period in geological history.

I learned from the last one: I’m going to look at the answer choices right away. They are: Cambrian period, Triassic period, Pliocene epoch, and Precambrian eon.

Hmm. One of the (many) timeframes shown on the charts is the beginning of three new division groupings: an eon, an era, and a period. Examine the graph. Only the second one shows eon, era, and period together, so let’s start there. The horizontal lines indicate the divisions between different eons, eras, and so on. Are there any where the horizontal lines go all the way across?

Yes! Towards the bottom, we have one horizontal line going all the way across, marking the Phanerozoic eon, the Paleozoic era, and the Cambrian period. Are any of those options in the answers? Yes, the Cambrian period.

The answer to the first question is 25%. The answer to the second question is the Cambrian period.

Key Takeaways for Graphics Interpretation questions:

(1) The Graphics Interpretation questions will always contain… a graph! You may see more traditional graphs, such as pie or bar charts, but you may also see more unusual graphs like the one we had in this problem. As a general rule, read the introductory text before examining the graph.

(2) Don’t try to understand or learn everything about the graph. Know how it works and what kind of information it gives, but that’s it. You don’t need to take down a bunch of notes about the details of the graph, though there may be times that you’ll want to jot down a note about how the graph works.

(3) The Graphics Interpretation questions can be less dense, and therefore faster to answer, than some of the other question types (such as Multi-Source Reasoning). You’ll probably spend a bit less time, on average, on these in order to spend more time on some of the more dense questions.

* All quotes copyright and courtesy of the Graduate Management Admissions Council. Usage of this material does not imply endorsement by GMAC.


  • I differ from the answer provided here.
    The question is "the BEGINING of which period marks the onset of ....",
    - Cambrian period cannot be the right answer because its 'end' marks the onset of a new period, and not its 'beginning'.
    Correct answer ought to be Precambrian eon, as with its BEGINING do a new eon, era, and period start.

    Please correct me if i am going wrong somewhere.

    • Whoops. Careful on how you're reading the diagrams. When we're talking about things that happened millions of years ago, the timeframe is "backwards" - something started 500 million years ago and existed until 400 million years ago, for example - so the smaller number represents a period *later* in time, not earlier in time. :) If you forget or overlook this, there's a clue in the diagram: "< 10,000 years" (or the numbers close to zero) are labeled "recent" on the diagram.

      The Cambrian started around 550 million years ago and ended around 520 million years ago.

  • Oh... Yes, you are right. Thanks for the reply.

  • Hi Stacey, wow, this chart is hard to digest. Having worked the problem prior to reading your rundown, I ended up staring at the graphic trying to decypher it for a while. Eventually I read the blurb and that helped a (a little...) Ultimately, I figured it out and answered both questions correctly. Then, I looked down at my stopwatch and... 3:28. Ouch.... How do you suggest I gain speed without sacrificing accuracy? --mj.

    • First of all, simply do more of these. I felt the same way the first time I started doing IR questions - they were just so foreign. One of the things you'll discover is that IR purposely gives us TONS more info than we actually need - which is very unlike quant and verbal. So part of the task is to figure out what we don't need / can ignore.

      For instance, if I get a chart or graph on a quant question (NOT IR), I'll usually examine the chart / graph first to understand it before I read the question, because there usually isn't a lot of extraneous info and the question is often designed to trip me up with regard to the data.

      But for IR, I always read the question first and figure out: what do I actually need here to answer this? Only then do I go looking for the data.

      Also, one more thing: DO sacrifice accuracy. :) You don't care about getting a great IR score (at this point anyway). Spend your study time where it matters: quant and verbal.

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