Archaeologists should make greater use of satellite images in their se

Question

Archaeologists should make greater use of satellite images in their search for Mayan ruins in the jungles of Guatemala. Though satellite photographs have proven unhelpful because of their inability to penetrate the dense tree canopy, infrared imaging translates heat signatures into distinct colors, making previously-undiscovered ruins visible.

The conclusion above is based on which of the following assumptions?

A. Infrared imaging is helpful because the heat signature of ruin sites is different from the heat signature of the surrounding jungle.

B. Archeologists in the field have not been able to discover many ruins because the jungle is impenetrable.

C. Archaeologists use both satellite technology and local folklore to theorize the location of ruins.

D. Archaeologists require special training in order to read maps produced by infrared imaging.

E. Satellite photography has not produced images of sufficient detail to locate ruins in the jungle.

I chose (e) since , "Satellite photography has not produced images of sufficient detail to locate ruins in the jungle, infrared imaging translates heat signatures into distinct colors..

Please elaborate .

GMATPill · Accepted Answer

If you apply the assumption negation technique, you may mistakenly choose (E). But it's incorrect.

Let's try the GMATPill approach. First focus on topic relevancy. Then apply assumption negation where necessary.

Topic relevancy. This depends on conclusion. What is the conclusion?

It's actually not the first sentence here. "Archaeologists should make greater use of satellite images..."

No, it's not that. It's more subtle here. It's:
 "Infrared....makes previously-undiscovered ruins visible"

Essentially, the passage changes direction and makes a new statement in favor of Infrared. Infrared is better than satellite because it "makes previously-undiscovered ruins visible".

Thus, the eliminate answer choices that don't affect "Infrared being a useful choice"

My gut instinct when reading:
"Infrared" better than "satellite" because of this heat signature advantage. But for this to be true, a "Mayan ruin" should indicate a heat signature and non-Mayan objects should not. That way if we do see a heat signal, we know it is a Mayan ruin.

But without that, let's go through the answer choices.

GMATPill Steps
Step 1:Check relevancy
Step 2: Then apply assumption negation if necessary: 
(A)
Is (A) relevant to "Infrared being a useful choice"? Yes. Now, apply assumption negation.
Original: Infrared imaging is helpful because the heat signature of ruin sites is different from the heat signature of the surrounding jungle. 
Opposite: Infrared imaging is helpful because the heat signature of ruin sites is NOT different from the heat signature of the surrounding jungle.

Opposite.....? ok well, if the heat signature of ruin sites is the SAME as the heat signature from surrounding jungle, then when we see our infrared results, we won't be able to distinguish what is Mayan, and what is jungle. We are UNABLE to distinguish and make visible the ruins. How does this compare to the conclusion of the original argument? It's opposite.

Thus assumption negation worked. 
Original -> Infrared helpful, ruins visible
Opposite -> Infrared not helpful, ruins not visible

Thus (A) is a good answer choice.

What about (E)? 
Is (E) relevant to "Infrared being a useful choice"? No.

No....(E) is actually talking about the "+" points of satellite photography...NOT about the "+" points about Infrared..which is what the argument's topic is. Thus...it's not a valid contender to apply assumption negation.

If you do mistakenly apply the assumption negation, you'll see that it might be a contender too. But that would be wrong,  it fails GMATPill's step 1, rule of relevancy .

Zarrolou · Answer

Facts:
Archaeologists should make greater use of satellite images.
Though satellite photographs have proven unhelpful because of their inability to penetrate the dense tree canopy.

Conclusion:
Infrared imaging translates heat signatures into distinct colors, making previously-undiscovered ruins visible.

The conclusion is based on the fact that infrared images give us more information than satellite photographs do.
Therefore we are looking for such assumption, and the only one that guarantes so is option A.
a) Infrared imaging is helpful because the heat signature of ruin sites is different from the heat signature of the surrounding jungle.  so infrared images will make "previously-undiscovered ruins visible".

adiagr · Answer

The argument states that satellite images have proven unhelpful, primarily because of dense canopies . The argument then mentions that infrared imaging would be helpful.
Now we have to choose that option which highlights "exactly what is the aspect that makes infrared imagery a viable option"

Let us review options:

A) This option highlights a distinct advantage of Infrared imaging. We would able to discern between canopies and ruin sites. Hold.
b) Premise being repeated. No additional info. Out.
c) This gives no info about Infrared imagery and focuses on the premise part. Out.
d) This option discusses about training aspects. No comment on why Infrared is better. Leave it. 
e) This is highlighting a shortcoming of satellite imagery. We already know that satellite imagery is not good enough. This is a premise booster. Reject this option.

(A) is the correct option.

Abhishek009 · Answer

Satellite images : Not helpful discovering Mayan ruins because images can not in penetrate dense tree canopy
Infrared imaging : Uses distinct colors as heat signatures ----> helpful in discovering Mayan ruins

Try to negate option (A)

Infrared imaging is helpful because the heat signature of ruin sites is as that of heat signature of the surrounding jungle.

It will not be helpful to discover previously undiscovered Mayan ruins visible.
 
b)Archeologists in the field have not been able to discover many ruins because the  jungle is impenetrable. 
 
Irrelevant

c) Archaeologists use both satellite technology and local folklore  to theorize the location of ruins.
 
Out of scope and irrelevant to the discussion.

d) Archaeologists require special training  in order to read maps produced by infrared imaging.
 
Out of scope of current discussion

e)  Satellite photography has not produced images of sufficient detail to locate ruins in the jungle.

This has already been stated in the first premises , and the statement is just a repetition of what has already been stated in different words...

Hence IMHO (A)

redskull1 · Answer

A is not a good answer at all.WHY infrared imaging is useful CANT be the assumption.It is kind of irrelevant I feel.Moreover the argument is telling that we CAN discover the ruins.The advantages of infrared at max are strengtheners.Experts Pls chip in.Doing such questions are, at least for a small reason, dangerous.

For what an assumption is pls see RONS videos dated Sept 27,2012 & Aug 8,2013

For what an assumption is pls see RONS videos dated Sept 27,2012 & Aug 8,2013

vasuca10 · Answer

VeritasKarishma  Mam is A more of a strengthener type answer choice? Kindly enlighten your views

aragonn · Answer

vasuca10

Let me try to give you a hand. following are my notes for assumption questions.

As usual let see the reasoning of the author first. Archaeologists used satellite images for finding more ruins but due to dense jungles, this method is not useful. an alternative is infrared imaging. What it does ? infrared imaging translates heat signatures into distinct colors, making previously-undiscovered ruins visible. At this point you should think about what can be assumption in these lines. that infrared is useful in the case of jungles. ofcource it will be useful if it does what it says it does. before even looking the answer choice you can say that.

Now your question. an option in assumption question can be strengthner. just it must pass the negation test. if two choices are as such apply negation test and check for correct answer. Remember have a plan for all type of question. and just execute that plan. Hope it was helpful.

vasuca10 · Answer

Hey thanks a lot mate  aragonn 
It was useful indeed.....Crux is assumption can always be strengthener and not vice - versa. Here we are talking about infrared imaging which is helpful because it is able to distinguish and make previously undiscovered ruins visible
Hence A is the best fit

redskull1 · Answer

I’d like to chip in if you dont mind.I am not trying to change ur understanding in any way...

2 really important features of an assumtion choice are probably as follows:
1)It has to be correct(it must be true) at any cost for the argument to hold.U may think of this feature as the negation test too..
2)An assumtion question cannot have strengtheners as answers surely,simply because negation test results on strengtheners give very weak answers.Negation test on assumptions gives us really pinpoint strong answers...

For the above mentioned reasons answer to an assumption question cannot have strengtheners as answers.A strengthen question definitely can have an assumtion as the answer.I feel we can resolve a lot many assumtion questions just by telling ourselves that THEY HAVE TO BE TRUE.

Expecting some nice comments from the forum members....

Posted from my mobile device

redskull1 · Answer

I respectfully would beg to differ from aragonn’s view...I myself got some clarity in this aspect after wathing the aforementioned Rons video’s( just watch the first example in both those video’s).The examples each last approximately 10mins.

Posted from my mobile device

Posted from my mobile device

aragonn · Answer

redskull1  - hey man, Your statement is not clear. Care to explain, of what point you have mentioned here ?

redskull1 · Answer

Hi bud...the part where you say “an option in an assumtion question can be a strengthener”

Posted from my mobile device

KarishmaB · Answer

Assumption questions are a special kind of strengthen questions - they are necessary for the conclusion to hold. Assumptions are missing, necessary premises. They will definitely strengthen the conclusion. The additional point is that they will be necessary for the conclusion to hold. Check out these posts for more on assumptions: https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2013/0 ... sumptions/ https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2013/0 ... -question/

SnorLax_7 · Answer

@GMATNinja/@KarishmaB/@GMATIntensive/@DmitryFarber/@egmat/EMPOWERgmatVerbal/@chetan2u
In this question, Are satellite photgraphs and Satellite images 2 separate thing ? What i have understood from this passage is that Satellite images are good not because of satellite photographs but because of another kind of satellite images (infrared Images).

MartyTargetTestPrep · Answer

Yes, in the context of this question "satellite photographs" and "satellite images" are two different things though, in general, photographs are a type of image.

VerbalBot · Answer

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Archaeologists should make greater use of satellite images in their se

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