CR: Of patients over 65 years old who survived coronary bypa

[cesar.rodriguez.blanco]

I do not understant how to deal with this CR. Please, help.
For example, why is E better than D?

Of patients over 65 years old who survived coronary bypass surgery - a procedure widely prescribed for people with heart disease - only 75 percent benefited from the surgery. Thus it appears that for one in four such patients, the doctors who advised them to undergo this surgery, with its attendant risks and expense, were more interested in an opportunity to practice their skills and in their fee than in helping the patient.

Which of the following, if true, most seriously undermines the argument?

A. Many of the patients who received coronary bypass surgery are less than 55 years old
B. Possible benefits of coronary bypass surgery include both relief from troubling symptoms and prolongation of life.
C. Most of the patients in the survey decided to undergo coronary bypass surgery because they were advised that the surgery would reduce their risk of future heart attacks
D. The patients over 65 years old who did not benefit from the coronary bypass surgery were as fully informed as those who did benefit from the surgery as to the risks of the surgery prior to undergoing it
E. The patients who underwent coronary bypass surgery but who did not benefit from it were medically indistinguishable, prior to their surgery, from the patients who did benefit.

[vrajesh.dave]

IMO E- is better than D for the following reason.

We are supposed to weaken the argument

argument is -- Doctors were more interested in an opportunity to practice their skills and in their fee than in helping the patient.

D -- says that all the patients were fully informed of the risks of the surgery. If the doctor knew that a certain patient won't benefit from the surgery, then also they were informed of the risks. [but is not that they will not benefit from the surgery]

E -- Medically doctors could not distinguish between patients who benefited from the surgery from those who did not.
This sentence truely weaken's the argument.

I hope this helps.

[RonPurewal]

IMO E- is better than D for the following reason.

We are supposed to weaken the argument

argument is -- Doctors were more interested in an opportunity to practice their skills and in their fee than in helping the patient.

D -- says that all the patients were fully informed of the risks of the surgery. If the doctor knew that a certain patient won't benefit from the surgery, then also they were informed of the risks. [but is not that they will not benefit from the surgery]

E -- Medically doctors could not distinguish between patients who benefited from the surgery from those who did not.
This sentence truely weaken's the argument.

I hope this helps.

well done.

the argument assumes that the doctors KNEW that the patients wouldn't have benefited from the surgery. choice (e) shoots down this assumption.

[Mymisc]

I found myself in a myth here, would someone please help to see what I missed in this argument.

I can see that E works very well to weaken the argument. But another weakening approach to this kind of problem is normally to identify some reasons that might also contribute to the different results for the two groups compared. If 'indistinguishable' in E is changed to something like "distinguishable" things, say the 1/4 patients already in worse shape before the surgery, the argumenet would be weakened as well.

So then, addressing either the "indistinguishable" traits or "distinguishable" traits of the two compared groups can weaken the argument, HOW CAN two opposites can reach the same goal of weakening? I felt something buried in the logical chain I am not aware of yet.

Thanks!

[RonPurewal]

I found myself in a myth here, would someone please help to see what I missed in this argument.

"myth"?
i'm not sure what you mean here, but you definitely don't mean "myth".
maybe "quandary" or "impasse"?

I can see that E works very well to weaken the argument. But another weakening approach to this kind of problem is normally to identify some reasons that might also contribute to the different results for the two groups compared.

i'm not sure what "method" you are referring to here, but it seems that you're over-thinking the problem.

in general, the best approach to these problems is just to take the answer choices, one at a time, and decide (from an unbiased standpoint) whether each choice strengthens or weakens the argument.
it's generally a bad idea to introduce irrelevant considerations, as you're doing here.

If 'indistinguishable' in E is changed to something like "distinguishable" things, say the 1/4 patients already in worse shape before the surgery, the argumenet would be weakened as well.

no, it wouldn't.
as it stands, this statement wouldn't substantively strengthen or weaken the argument, because we don't know enough about whether the doctors were aware of the difference -- remember that the main point of the argument is about the doctors' motivations in performing the surgery, not about the outcome of the surgery per se.

if your escalated this statement by including the fact that the doctors knew about this difference in health, then this statement would actually strengthen the argument somewhat, because it would indicate that the doctors were still performing the surgery even on patients with a low chance of a positive outcome.

--

So then, addressing either the "indistinguishable" traits or "distinguishable" traits of the two compared groups can weaken the argument, HOW CAN two opposites can reach the same goal of weakening? I felt something buried in the logical chain I am not aware of yet.

hmm

well, is easy to construct examples in which both a statement and its opposite could weaken a conclusion.
for instance, off the top of my head:
The roster of voters from Townville includes three people named "Morgan". since this name is commonly given to both men and women, it's impossible to determine whether these voters are male or female.

consider:

(a) In Townville, the name "Morgan" is traditionally given to females.
--> WEAKEN
... because this means that the "morgan"s are probably women.

(b) In Townville, the name "Morgan" is not traditionally given to females.
--> WEAKEN
... because this means that the "morgan"s are probably men.


here, we have an example in which each of two opposite statements would be a weakener.

--

in general, though, the main point is that you should only consider the effect of the statements that are actually given!

you have your hands full enough with these statements; the last thing you want to do is exacerbate the difficulty by introducing irrelevant considerations.

[s.ashwin.rao]

I would ask why not C? Actually C provides an alternate reasoning for more number of patients undergoing the operation with less success rate. I thought alternate reasoning has higher prio in weaken questions.

I don't know but more often than not I am getting into this funny situation that I have two answers with me and I almost always select the wrong one. This has become real serious problem.

Any Golden thumb rule for CR when you two answer choices please?

Thanks

[jnelson0612]

I would ask why not C? Actually C provides an alternate reasoning for more number of patients undergoing the operation with less success rate. I thought alternate reasoning has higher prio in weaken questions.

I don't know but more often than not I am getting into this funny situation that I have two answers with me and I almost always select the wrong one. This has become real serious problem.

Any Golden thumb rule for CR when you two answer choices please?

Thanks

C doesn't directly weaken the conclusion that for one-fourth of patients doctors were more interested in practicing their skills and collecting fees than in helping patients.

Look at the premise: 75% of people over 65 who undergo the procedure are helped and 25% are not. From that we are concluding that for 25% of patients doctors are doing the surgery only to gain experience and collect fees.

The best way to weaken an argument is to attack the assumption. There is a huge logic gap between saying that 25% of the patients were not helped by the surgery, thus the doctors performing the surgery on these people only did it to benefit themselves, the doctors. To conclude this we have to assume that the doctors KNEW the surgery would not benefit the patients but did it anyway to gain experience and fees. To weaken the argument, negate this assumption.

If you can deconstruct the argument this way you are much more likely to find the right answer.

[s.ashwin.rao]

Thanks

[RonPurewal]

Thanks

(:

[s.ashwin.rao]

Sorry Nelson/Ron,
Just one clarification, so you say that 25% of patients not bieng helped is a huge number for us to not consider C and that if 25% of the patients were not helped then that number must be due to doctors greed, hence E?

Thanks again.

[tim]

No. the magnitude of the 25% number is irrelevant. the point here is that the conclusion talks about that 25% of people, but answer C says something about the other 75%, which has nothing to do with the 25% we are talking about..

[s.ashwin.rao]

Wow...This time I am clear. Thank you very much Tim.

[RonPurewal]

Wow...This time I am clear. Thank you very much Tim.

glad it helped

[anupa_panjari]

Hi Ron

When I was answering the question I was stuck between D and E. I also read in the post that the best way to attack is to negate the assumption. Could you please explain how to negate the assumption to select between D and E.

I would like to learn this method of negating the assumption.

Thanks

[RonPurewal]

Hi Ron

When I was answering the question I was stuck between D and E. I also read in the post that the best way to attack is to negate the assumption. Could you please explain how to negate the assumption to select between D and E.

I would like to learn this method of negating the assumption.

Thanks

jamie (jnelson0612) explained this solution to the problem at hand in his post above (post49248.html#p49248).if you don't understand his explanation, please point out exactly what you don't understand, and perhaps he'll be able to clarify for you.

in general, if you can use your intuition about the argument to see what is being assumed, then "weakeners" are usually going to be statements that shoot down one of those assumptions. however, there is no systematic way in which you can find the assumptions themselves, other than to understand the flow of the argument in general and then deduce where it has "holes" or where something is "missing".