#2 - Although 90 percent of the population believes itself

[lsatjourneygirl]

I understand why answer choice D is right, and this is what I choice, but A made me feel uncomfortable. Can you explain why it is wrong?

Thank you!

[lsatjourneygirl]

?

[Stephanie Oswalt]

Hi lsatjourneygirl,

Thanks for your question. Generally speaking, we need a bit more input from you before we delve into a discussion of a particular LR question. Ultimately, it won't be us who are taking the test; it's you! Our goal is to help you cultivate the analytical ability to approach these questions on your own, which is why you need to help us help you first.

Here's what I'd like you to do:

• 1. Describe your approach to the stimulus. Did you understand the argument, if any, from a structural standpoint? What is the conclusion, and what evidence is the author using in support of that conclusion?
  
  2. Did you prephrase an answer to the question in the stem? If so, what was your prephrase?
  
  3. What exactly made the two answer choices you have listed particularly attractive? Did you use any question type-specific test (e.g. Assumption Negation Technique) to differentiate between them?

Thanks,
Stephanie

[jlam061695]

I think the reason why I did not choose D was due to the nature of the answer; it felt like the answer to a justify the conclusion and/or an assumption question. Because if you add D, which states that "an understanding of DNA is essential to making well-informed medical choices or good public policy decisions" to the argument, it serves as the link between the premise that states "only 20% of the population knows enough about DNA to understand a news story pertaining to DNA" and the conclusion, which assumes that answer choice D is true. I guess what I am trying to say is that D did not fit into my conception of what a correct answer to a flaw in the reasoning question is.

[Jonathan Evans]

Jlam,

You make an excellent observation:

I guess what I am trying to say is that D did not fit into my conception of what a correct answer to a flaw in the reasoning question is.

A slight modification of the way you approach these questions is in order. The question types are themselves categories into which we assign similar tasks; however they are not all identical to one another. It is important that you read and understand every question per se. Take this question for example:

"The argument's reasoning is questionable because the argument fails to demonstrate that"

This Flaw question could be asked differently. We might be given simply:

"The argument's reasoning is questionable because"

In this case we have a classic Flaw question: find a matching description of the erroneous reasoning in the argument.

In contrast, you might have a Flaw question like the following:

"The argument's reasoning is questionable because the author fails to rule out the possibility that"

In this case, the question is a Flaw question, but the answer will be something that will weaken the validity of the conclusion. It is, in effect, a weaken task.

Or, you might encounter a question such as the following:

"The argument's reasoning is questionable because the author presupposes that"

This question stem is analogous to that of this problem. The information that the author "fails to demonstrate" is an assumption, a condition necessary for the truth of the conclusion. Therefore, this particular answer D is not in fact a Justify the Conclusion type answer (those questions look for conditions sufficient to ensure a valid conclusion); instead answer choice D contains a necessary condition. You can actually do the negation test on it. What if "an understanding of DNA were essential neither to making well-informed medical choices nor to good public policy decisions?" In this case, the conclusion does not follow.

In conclusion, you should note that you must read the question stem to understand the nuance of what it is looking for. This skill is particularly pertinent to Flaw questions, as illustrated above, but is of some importance when dealing with other questions (such as Must Be True) as well.

[jlam061695]

Thanks for answering my question; you provided a very helpful explanation!

[Tony_Stark]

Hello, I'm having some confusion with D and I am looking for some clarity.

In the premise is:
~DNA -> ~Medical Concepts OR ~Public Policy Decisions

ANS D:
Medical Concepts OR Public Policy -> DNA

My question is, when you take the contrapositive of the OR statement - shouldn't it turn into an AND statement?

Thanks in advanced

[James Finch]

Hi Tony,

I need to caution against overconditionalizing. This flaw question is similar to an assumption question, where the stimulus relies upon a linkage between premises to logically justify the conclusion, but we don't need to turn it into conditional reasoning to reach the correct answer. All that is required is a recognition of a hole in the reasoning.

In this case, the premise is that only 20% of the population understand DNA, and the conclusion that 80% do not know enough about medical concepts to make well-informed personal medical choices or good public policy decisions about health care.

As a flaw question, there is some issue with the reasoning, and the obvious issue is a link between the premise and the conclusion. So what is missing between premise and conclusion? The 80/20 percentage split works, but only if one assumes knowledge of DNA is necessary for medical decisions generally--the linkage is not given in the stimulus.

Answer choice (D) gives us that link, and thus is the correct answer.

Hope this helps!

[gwlsathelp]

To me, answers A and D are very similar. Can someone break down why A is not an assumption made by the stimulus? I understood that the author was making an assumption connecting the understanding of DNA to medical concepts, but could not find anything that matched that pre-phrase and A and D were the closest.

[Robert Carroll]

gw,

20% of the population knows enough about DNA to understand a news story about it, but note that the author says that at least 80% of the population doesn't know enough about medical concepts to make well-informed choices. The author is not committed to thinking that any of the 20% who understand DNA can make those choices, because "at least 80%" is compatible with 100% - the author has expressed words that allow the author to think that no one knows enough about medical concepts to make the choices mentioned. In short, the author is not saying that anyone can make well-informed choices - the author's argument is purely putting an upper limit, not putting a lower limit, on the number of people who can make well-informed choices.

Answer choice (D), on the other hand, claims something is necessary for making choices. The lack of that necessary condition would make someone unable to make choices. And that's what the author is doing - trying to show that a relatively low number of people can make those choices, but based on a requirement that might not be the appropriate one here.

Robert Carroll