akela
People who browse the web for medical information often cannot discriminate between scientifically valid information and quackery. Much of the quackery is particularly appealing to readers with no medical background because it is usually written more clearly than scientific papers. Thus, people who rely on the web when attempting to diagnose their medical conditions are likely to do themselves more harm than good.
Which one of the following is an assumption the argument requires?
(A) People who browse the web for medical information typically do so in an attempt to diagnose their medical conditions.
(B) People who attempt to diagnose their medical conditions are likely to do themselves more harm than good unless they rely exclusively on scientifically valid information.
(C) People who have sufficient medical knowledge to discriminate between scientifically valid information and quackery will do themselves no harm if they rely on the web when attempting to diagnose their medical conditions.
(D) Many people who browse the web assume that information is not scientifically valid unless it is clearly written.
(E) People attempting to diagnose their medical conditions will do themselves more harm than good only if they rely on quackery instead of scientifically valid information.
Source: LSAT
Though (C) is appealing many, it is very clearly wrong using the concept of "scope." Option (C) is out of scope.
People browsing med info cannot distinguish between science and quackery (non scientific).
Quackery is particularly appealing to readers with no medical background.
Conclusion: People diagnosing through web are likely to do themselves more harm than good.
We need an assumption - something that will plug the gap between the premises and the conclusion. Note that the premises do not even mention harm so the assumption will likely relate to that.
(A) People who browse the web for medical information typically do so in an attempt to diagnose their medical conditions.
Not correct. We don't need to assume that people typically browse medical. info to diagnose. Even if only 20% of the people browsing are doing so to diagnose, the conclusion still holds.
The conclusion specifically concludes about people who attempt to diagnose through the web - whether these are 20% of people browsing or 80% of people browsing, it doesn't matter.
(B) People who attempt to diagnose their medical conditions are likely to do themselves more harm than good unless they rely exclusively on scientifically valid information.
Unless = If .. not ...
If people do not rely exclusively on science, they are likely to do themselves more harm.
In other words, we are saying that if people rely on quackery, they are likely to do themselves more harm than good.
Our argument does assume this. It does assume that quackery (non science) causes more harm than good.
If you are not sure, let's plug it in the premises and then look at our conclusion.
People browsing med info cannot distinguish between science and quackery (non scientific).
Quackery is particularly appealing to readers with no medical background.
If people rely on quackery, they are likely to do themselves more harm.
Conclusion: People diagnosing through web are likely to do themselves more harm than good. Does make more sense now, right?
The assumption is necessary for the conclusion. If we negate it (If people rely on quackery, they are NOT likely to do themselves more harm) then the conclusion doesn't make sense.
(C) People who have sufficient medical knowledge to discriminate between scientifically valid information and quackery will do themselves no harm if they rely on the web when attempting to diagnose their medical conditions.
Out of scope. The argument is discussing people who are unable to discriminate between science and quackery. What appeals to them, how they may harm themselves etc. The small percentage that is able to make this discrimination is out of scope for us. We are only talking about people who cannot discriminate.
Think of the entire universal set of all people. Say some of them browse the net for medical info (consider a circle inside the universal rectangle). Of these, most (say 90%) cannot discriminate between science and quackery. So we are saying that they usually cause themselves more harm than good. What happens to the other10%, we don't know and we don't care.
(D) Many people who browse the web assume that information is not scientifically valid unless it is clearly written.
Not true. People assume nothing about validity of info that is clearly written. They just like that info more. It seems they do not question the validity of the info in either case - clearly written or not.
(E) People attempting to diagnose their medical conditions will do themselves more harm than good only if they rely on quackery instead of scientifically valid information.
Option (E) says "Only if people rely on quackery, they will do themselves more harm than good."
This is not an assumption of the argument. People could do themselves more harm than good if they rely on scientific. info too since they wouldn't know how to use the scientific info properly.
Answer (B)