Q5 - Toxicologist: A survey of oil

[bigtree65]

I'm very confused, I thought the one answer that does not strengthen the conclusion, that there will be an increase in headaches fatigue and shortness of breath, was A. We know that an alarming number of workers that work with MBTEs get these symptoms but the author never mentions how many workers get them exactly. So if the number is say 49 out of 100 then most of these workers don't have any symptoms. Now for the other group, if 49 out of 100 workers who do not work with MBTEs do get symptoms then most of them dont have any symptoms and A doesn't tell us anything because we can potentially have the same number of workers in the two different groups with symptoms and MBTEs don't have any impact on symptoms. B on the other hand tells us that there is another reason to expect fatigue, headaches and shortness of breath to increase. So how is the answer not A?

[timmydoeslsat]

I was a little confused by your scenario you posited in the first post. If you would please make it more clear to me or edit the scenario, I will be glad to help.

In this problem, we have a strengthen EXCEPT question. The correct answer will NOT strengthen our argument (conclusion). The four wrong choices will strengthen the argument.

Our stimulus gives us a correlation between MBTE and incidence of complaints with an array of symptoms.

We do not know that MBTE caused these symptoms, but we do know that workers who work with MBTE underwent symptoms.

It is also stated that MBTE will soon be widely used.

The conclusion of the toxicologist's argument is that we can expect an increased incidence of headaches, fatigue, and shortness of breath.

The toxicologist is asserting the cause of the symptoms to the MBTE.

On these strengthen EXCEPT questions, I like to go through each one and see if the answer choice strengthens the argument. If it does, I eliminate it.

A) This strengthens the idea of MBTE being the cause. You can strengthen a cause and effect argument by:

Cause not present - Effect not present
Cause is present - Effect is present

This answer shows that when MBTE is not present, the effect is not present.

B) This does not strengthen the idea that MBTE is the cause. This tells us that the symptoms listed from the stimulus could have been derived from other medical conditions. This is our answer.

C) This shows when the cause was present, so was the effect.

D) This shows cause and effect with the MBTE juxtaposed to regions without the cause, and those regions did not have the effect.

E) This is a classic argument booster that tells us the sample from the survey is representative.

[noah]

Another stellar explanation!

To the original poster, I see what you mean about your scenario - basically, can't we manipulate the numbers so that (A) doesn't strengthen? Yes, we could, but we'd also have to interpret "alarming" as being a relatively small number. And, notice how much work you have to do to make (A) not strengthen. I think you should step back and look at it a bit more plainly:

The conclusion is that we can expect some health issues. Why? Because gas with MBTE will be available soon, and we see an alarming number of illnesses among folks that work with MBTE.

What's the gap? Well, maybe those folks are getting sick from something other than the MBTE. It's not hard to imagine that working at an oil-refinery might carry some other health risks!

What we see in the answer choices is that the wrong ones strengthen the relationship between MBTE and illness. What we see in the correct answer, (B), is that these illnesses can also show up from other causes (conditions). But since that data is quite broad in that we don't know how often folks get sick from these other causes and in that we don't know how the oil-refinery folks fit in (are they getting these other conditions?), (B) ends up being just a random fact.

Let me lean on Tim for the wrong answer explanations:

A) This strengthens the idea of MBTE being the cause. You can strengthen a cause and effect argument by:

Cause not present - Effect not present
Cause is present - Effect is present

This answer shows that when MBTE is not present, the effect is not present.

Yes, the answer isn't as strong as it could be since it only says that "most" of these workers don't get sick from MBTE, but it does help address the concern that perhaps oil-refinery workers are getting sick from something else. (A) gives us some data that indicates otherwise.

B) This does not strengthen the idea that MBTE is the cause. This tells us that the symptoms listed from the stimulus could have been derived from other medical conditions. This is our answer.

C) This shows when the cause was present, so was the effect.

D) This shows cause and effect with the MBTE juxtaposed to regions without the cause, and those regions did not have the effect.

E) This is a classic argument booster that tells us the sample from the survey is representative.

[WaltGrace1983]

I've got a question. I understand that (C), (D), and (E) are obviously wrong and (B) is obviously right. However, I had the most trouble eliminating (A). I understand that ~cause → ~effect is a good way to strengthen the argument. This definitely gives us ~cause, saying that "workers who do not work with MBTE...". However, does it really give us the ~effect?

To me, this stimulus is basing the conclusion on the assumption that MBTE caused the workers to have headaches, fatigue, and shortness of breath. Or at the very least, they complained about it. However, it never says that they developed any kind of serious health problems. In addition, it never says anything about health problem. Thus, what am I missing here in this incredibly nitpicky interpretation? It seems that the better answer would be "Most oil-refinery workers who do not work with MBTE do not complain about/have incidences of headaches, fatigue, and shortness of breath."

The "health problems" through me off but I guess you could make the argument that the "increased incidence of headaches, fatigue, and shortness of breath" are indeed related to health problems. Either way, this doesn't matter as much when (B) is so blatantly correct but maybe there is something I can learn here.

[maryadkins]

You're right about this:

I guess you could make the argument that the "increased incidence of headaches, fatigue, and shortness of breath" are indeed related to health problems. Either way, this doesn't matter as much when (B) is so blatantly correct

I think the lesson here is what Noah was saying to the other poster who was drawn to (A). See how hard you're having to work to make (A) not strengthen? Try to keep it simple wherever possible.