GMATPrep Reading Comp: Tackling a Science Passage - Part 1
Science topics on the GMAT can be hard to process. Lets face it, some of these topics are pretty tedious in addition to pretty technical.
How to get past that and do well? Think of a friend who likes these topics and tell yourself that youre learning this because you know s/he will want to know. Youre just trying to understand enough that you can tell your friend about it later.
Heres what were going to do. I have a passage and three questions for you, straight from the GMATPrep free exams. Give yourself approximately 6 to 7 minutes (on the shorter end if youre a faster reader and/or like science; on the longer end if youre a slower reader and/or hate this topic).
Finally, if you dont know anybody who likes the topic, Ill be your friend! Pretend youre trying to learn enough to tell me about the passage when youre done.
Ready? Go!
Prior to 1965 geologists assumed that the two giant rock plates meeting at the San Andreas Fault generate heat through friction as they grind past each other, but in 1965 Henyey found that temperatures in drill holes near the fault were not as elevated as had been expected. Some geologists wondered whether the absence of friction-generated heat could be explained by the kinds of rock composing the fault. Geologists pre-1965 assumptions concerning heat generated in the fault were based on calculations about common varieties of rocks, such as limestone and granite; but "weaker" materials, such as clays, had already been identified in samples retrieved from the fault zone. Under normal conditions, rocks composed of clay produce far less friction than do other rock types.In 1992 Byerlee tested whether these materials would produce friction 10 to 15 kilometers below the Earth's surface. Byerlee found that when clay samples were subjected to the thousands of atmospheres of pressure they would encounter deep inside the Earth, they produced as much friction as was produced by other rock types. The harder rocks push against each other, the hotter they become; in other words, pressure itself, not only the rocks properties, affects frictional heating. Geologists therefore wondered whether the friction between the plates was being reduced by pockets of pressurized water within the fault that push the plates away from each other.
1. The passage suggests which of the following regarding Henyeys findings about temperature in the San Andreas Fault?(A) Scientists have yet to formulate a definitive explanation for Henyeys findings.
(B) Recent research suggests that Henyeys explanation for the findings should be modified.
(C) Henyeys findings had to be recalculated in light of Byerlees 1992 experiment.
(D) Henyeys findings provided support for an assumption long held by geologists.
(E) Scientists have been unable to duplicate Henyeys findings using more recent experimental methods.
2. The passage is primarily concerned with(A) evaluating a method used to test a particular scientific hypothesis
(B) discussing explanations for an unexpected scientific finding
(C) examining the assumptions underlying a particular experiment
(D) questioning the validity of a scientific finding
(E) presenting evidence to support a recent scientific hypothesis
3. According to the passage, Henyey's findings in 1965 were significant because they(A) revealed an error in previous measurements of temperature in the San Andreas Fault zone
(B) indicated the types of clay present in the rocks that form the San Andreas Fault
(C) established the superiority of a particular technique for evaluating data concerning friction in the San Andreas Fault
(D) suggested that geologists had inaccurately assumed that giant rock plates that meet at the San Andreas Fault generate heat through friction
(E) confirmed geologists' assumptions about the amount of friction generated by common varieties of rocks, such as limestone and granite
First, lets deconstruct that passage. Heres the Passage Map I created as I read the passage:
(P1) Pre-65, G: RPs heat via friction
65, H: not so hot
Why? Type of rock? Less L and G, more C? C = less friction
(P2) 92, B test: C same friction w/pressure. > press > heat
water reduce friction?
Whats the basic story here? Before 1965, there was a certain theory. Then H tested the theory but the data didnt support the theory. It's still the case that temperatures aren't as hot as expected. So the Gs came up with a new hypothesis to explain Hs results.
But then, in 1992, B tested this new theory and found that this new theory still doesn't explain why the temps aren't as hot as expected (as H found)! So the Gs came up with yet another hypothesisand then the passage ends.
I was actually a little annoyed when it ended. I want to know what the rightexplanation is!
Notice that my Map does get into the details of the story, but my re-telling of the story doesnt. As Im jotting down my notes, my brain is trying to put together that big picture or what we call the simple story. Just the practical storynot all the technical jargonbecause the story is what Im going to tell my friend who actually is interested in geology.
When Ive got that Simple Story set in my brain, its easier for me to remember some of the technical details about the heat and the friction. Theyre just details of an overall cohesive story that I actually understand. So when my friend asks a couple of questions, I can actually recall and relay a few of the details, toothough, at some point, Im going to tell my friend that she can go read the story herself if she really wants all of the details. :)
Lets take a look at the first question.
The passage suggests which of the following regarding Henyeys findings about temperature in the San Andreas Fault?(A) Scientists have yet to formulate a definitive explanation for Henyeys findings.
(B) Recent research suggests that Henyeys explanation for the findings should be modified.
(C) Henyeys findings had to be recalculated in light of Byerlees 1992 experiment.
(D) Henyeys findings provided support for an assumption long held by geologists.
(E) Scientists have been unable to duplicate Henyeys findings using more recent experimental methods.
On RC, the first step is to identify what type of question youve got. In this case, the word suggests signals that this is an Inference question. On inference questions, you need to find some detail in the passage and then figure out what else you can conclude must be true based on that detail.
So which detail is the right detail to examine? The question stem references Hs findings about temperature in the San Andreas fault. The passage talked about Hs tests in the first paragraph, so go up there and scan to see what his findings about temperature were.
Henyey found that temperatures in drill holes near the fault were not as elevated as had been expected.
Oh, right, H tested the old theory and discovered that the data didnt match. The theory said that the temperature should be higher, but H discovered that it wasnt that high after all. What can we infer from that?
Actually, they never did figure out why the temperature was so low, right? They used Hs findings to come up with a new hypothesis, but then B showed that one wasnt right either, so they came up with yet another hypothesisso, really, the conclusion is that there isnt one. We still don't know why the temperature was lower than expected.
Check the answers.
(A) Scientists have yet to formulate a definitive explanation for Henyeys findings.
Yes, this sounds like what we said: they keep generating hypotheses, but they havent found one yet that definitely works. Leave this choice in.
(B) Recent research suggests that Henyeys explanation for the findings should be modified.
Careful! H didnt offer an explanation (at least, not according to the passage). The geologists are the ones continually offering new hypotheses. They may very well have to modify their explanation yet againbut H doesnt need to modify anything. Eliminate answer (B).
(C) Henyeys findings had to be recalculated in light of Byerlees 1992 experiment.
B didnt test the same thing as H; B tested a different aspect of the theory entirely. Therefore, Bs findings wouldnt require H to have to recalculate anything. Eliminate this choice.
(D) Henyeys findings provided support for an assumption long held by geologists.
Trap! This is the opposite of what the passage says. Hs findings undermine the geologists long-held assumption that the temperatures would be a lot higher. Eliminate choice (D).
(E) Scientists have been unable to duplicate Henyeys findings using more recent experimental methods.
The passage does talk about later tests (by B), but B tests something else, not what H tested. Nor does the passage mention any other tests or experiments. Eliminate this choice.
The correct answer is (A). The passage doesn't come right out and say that the geologists cant explain Hs findings, but the fact that they have to keep coming up with new theories every time new information comes to light indicates that they havent yet figured out the right explanation.
Next time, well take a look at the second question in the group.
Key Takeaways for RC
(1) Map the passage. Make sure to delineate each paragraph and represent the main message (but not all of the details) in your map.
(2) As you make your Map, articulate the Simple Story to yourselfand keep it very big picture. What will you tell your friend afterwards? You wouldnt get into all of the specific details; youd mostly just tell her the main ideas / simple story.
(3) Inference questions require you to go a bit beyond what the passage explicitly statesjust be careful not to go too far beyond. What you infer has to tie very tightly to what you were given; you should be able to conclude with near-scientific precision.
* GMATPrep questions courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.