#16 - Tissue biopsies taken on patients who have undergone

[Rachael Wilkenfeld]

Hi bukkaabh,

You have a good instinct to think potential alternate causes here. However, in this case, the surgery couldn't have been a cause of the abnormalities because they existed when the surgery occurred. The abnormalities weren't discovered after surgery, they existed at the time of the surgery. One important aspect of causal reasoning is that the cause must occur before the effect. In this case, the effect (abnormality) would have occured before your potential cause (surgery). It's not that the surgery is irrelevant; it's how the doctors were able to observe and remove the abnormalities for testing. But it can't be the cause of the abnormalities.

Hope that helps!
Rachael

[hrhyoo]

Hi Powerscore,

After reading the stimulus, I thought the biggest issue was the sample/data - throat patients do not correcly represent the general population. So when I was torn between E and D, I picked E because it reduces the unrepresentativeness of the sample since both the patients and the general population would snore about the same. However, one of the previous posts states that D makes the problem of representation worse but I don't see how. Could you please explain this?

Hanna

[Adam Tyson]

I'm not seeing where we said that answer D makes the sampling issue worse, Hanna, but there was some discussion about the correlation being about snoring and throat damage rather than between snoring and throat surgery. If we assume that throat damage is what leads to surgery, then I can see how some folks might say that answer D makes things worse. We would want the people who snore to damage their throats and then get surgery to correct the damage, so that the surgical patients would snore much more than those who were not patients. But that might be assuming too much, because surgery could be due to any number of other causes, and not everyone with the damage might get surgery to correct it.

This argument breaks down somewhat simply to "these two things are correlated, so one of them caused the other." In any argument like that, there exists the possibility that the cause and effect are reversed, with the second thing causing the first, and eliminating that possibility, as answer E does, strengthens the original claim by removing that potential problem.

[j199393]

Hi,

If the conclusion is: "This shows that snoring can damage the throat of the snorer," can we assume that when the author refers to "the snorer," they are only referring to those who have gotten throat surgery, and not all people who snore?

This is what threw me off—I thought the conclusion was too general based on the information in the stimulus, which led me to select answer choice D, which addresses people who have and have not gone through surgery. Any clarification on this would be very helpful.

Thanks!

[Luke Haqq]

Hi j199393!

Happy to explain this one a bit more thoroughly. First, you ask,

can we assume that when the author refers to "the snorer," they are only referring to those who have gotten throat surgery, and not all people who snore? This is what threw me off—I thought the conclusion was too general based on the information in the stimulus

On the one hand, the language in the conclusion of this stimulus (which you correctly identify) doesn't give any reason for us to conclude that it is only talking about snorers who have had throat surgery. Rather, its language is about snorers generally. On the other, I do certainly understand and agree with your view that the conclusion is too strong based on the premises given alone. Indeed, one reason it seems too strong is that it is a general conclusion but is based only on consideration of a small group (those who have had throat surgery).

Whether or not the conclusion is fully warranted given the premises, the question stem asks us to strengthen the argument. The argument of the conclusion is about a causal relationship:

cause effect
snoring throat damage

There are five main ways to strengthen a causal argument on the LSAT: (1) show that the cause is always followed by the effect, (2) show that the effect is always preceded by the cause, (3) eliminate possible alternative causes, (4) eliminate the possibility that the causal relationship is reversed, and (5) validate that there are no problems with the data being used to show this causal relationship. Here, answer choice (E) states, "The abnormalities in the throat muscles discovered in the study do not cause snoring." In other words, answer choice (E) strengthens the causal argument by doing (4)--it denies the possibility that the causal relationship is reversed.

By contrast, answer choice (D) states, "People who have undergone throat surgery are no more likely to snore than people who have not undergone throat surgery." The conclusion of the stimulus is arguing that a causal relationship exists, but this answer choice doesn't address that causal claim that snoring causes throat damage.

[lsatryan]

Hello, I understand why E is the correct answer but I am still not fully sold on C being incorrect

[KelseyWoods]

Hi Ryan!

It would help to know a little more specifically what it is you like about answer choice (C). But, in this question, we're trying to strengthen a specific causal conclusion based on a correlation. The problem with drawing a causal conclusion from a correlation is that 1) we don't know if the two correlated conditions are causally related at all and 2) if there is a causal relationship, we don't know the direction of that relationship. As others have noted, answer choice (C) doesn't really do much to strengthen that there is a causal relationship between throat damage and snoring and it also doesn't strengthen what the direction of that relationship would be at all. Answer choice (E) does a much better job of strengthening the direction of the causal relationship because it eliminates the reverse cause and effect. Thus, answer choice (E) is a stronger answer.

But let us know if there's something specific you still like about answer choice (C)!

Hope this helps!

Best,
Kelsey

[amandas3]

Hello! Although I recognize how E strengthened the argument I really struggled to eliminate anything other than answer choice A, and am still not confident I fully understand why the others are wrong.

B: This choice seemed the least helpful because regardless of the purpose of the surgery the difference between non/snorers existed, and that difference prompted the conclusion. That being said, I could see the reverse of this choice being even more damaging to the already-problematic sampling issue

The conclusion referenced all snorers despite the sample being only people who got surgery, and this choice seemed to somewhat address the issue. If surgery/the sample population was limited only to people who already had abnormalities, beyond simply being a highly exclusive sample it leaves no room to even acknowledge potential snorers without abnormalities (or those who don't need/want/have access to surgery, etc), which would be necessary to make generalizations about snoring. While B) doesn't create a perfect sample, it seems to at least eliminate a possibility that would weaken the argument.

C: I definitely see how making the sample population even more exclusive/less representative would make the results less reliable, but it also eliminates possible alternative causes, right?

D: I get that the conclusion isn't concerned with the relationship between snoring and throat surgery. However, the sample only included people with throat surgery, making the implications of this choice potentially relevant to the reliability of the data. If surgery recipients are more likely to snore, this introduces a possible sample skew that wasn't addressed

E: I understand that this choice eliminates the possibility of the reverse causal relationship, which would seriously undermine the conclusion. However, if I apply the implications of this choice to the study it doesn't seem significantly more problematic than the other choices to me.

Even if the abnormalities could cause snoring, it doesn't change the fact that abnormalities exist without snoring, nor does it impact the observed relationship between severity of snoring and abnormality seriousness. Even if abnormalities initially cause the snoring, possibilities such as mutual exacerbation could exist and would be consistent with the assertion that snoring can cause damage. Or even if snoring leads to most abnormalities but some types of abnormalities cause snoring, for example, the author's use of the word can makes it seem very possible for the reverse causal relationship to coexist with the theory described without necessarily violating the conclusion.

It seems a big issue for me was the disconnect between the study's population being surgical recipients and the conclusion being about snorers in general. obviously the argument is purposely flawed and vague, but it tripped me up more than usual trying to figure out what aspect was the most necessary to strengthen and I think I started way overthinking. Hopefully I made some sense despite the rambling!

[Beth Hayden]

Hi Amanda,

Let's look at each answer choice:

B: The study looked at a group of patients who had throat surgery and then divided them into frequent snorers and rare/non snorers. It doesn't necessarily matter why they underwent the surgery because everyone in both groups had some kind of throat surgery. Even if everyone involved had an abnormality, that doesn't impact the conclusion, because the conclusion talks about serious abnormalities.

C: This isn't a terrible answer--generally a scientific study is better when there are fewer variations between the test subjects. But other than that it doesn't do much for the argument, it doesn't help strengthen the causal connection. Also, the idea is that snoring caused the abnormalities, it doesn't really matter what caused the snoring itself.

D: Sure, if say 90% of people who had throat surgery snore, that makes it a pretty shaky study, but that doesn't do a ton for the argument. There are a lot of medical studies done on skewed samples and they still have merit. Here they likely looked only at surgery patients because they were people who were already getting a biopsy taken anyway, so that's not a huge red flag for me.

E: This is the best answer because it addresses the most serious problem with the argument. Sure, maybe the study is imperfect, but the much bigger problem with the argument is that it ignores the possibility of reverse causation. If the reverse of C or D were true, it might very slightly weaken the argument. But if the reverse of E is true, the conclusion is very, very unlikely to be true! To answer your point on this, a strengthen answer choice does not have to prove the conclusion. It just has to make it more likely that the conclusion is true, and E does that.

Remember, you want the answer choice that most strengthens. You may not be able to completely rule out every other answer choice, but when you compare them to (E), they just don't hold up. Of course there could have been a correct answer choice that targeted the issue with generalizing to the full population, but the test writers focused on the bigger problem of potential reverse causation.

I hope that helps, but please let me know if there is anything that is still unclear!

Beth

[yufenz]

Hi there,
Great explanations! I see that the main focus of the question is on the causal relationship between snoring and tissue abnormalities.

Just a few more words on choice C. I was wondering if C could be a correct answer if it is phrased in this way: "Factors such as age, weight, and states of health also contribute greatly to the development of throat abnormality; however, people examined in this study are all very similar in those aspects".

I believe if C is phrased in this way, it would be a viable choice since this eliminates other possible causes of the same effect.

And E is undoubtedly the answer to this question since it rules out the possibility of a reversed causal relationship.

Looking forward to seeing some replies. Thanks!