Q18 - Bookstore owner: Consumers should

[the_sork]

Could anyone please explain this question to me? I guess my problem is that I don't understand what it's asking. Is it classified as a strengthen question?

Thanks!

[ohthatpatrick]

'Tis true that knowing what this question wants from you is what will make or break your success in answering it quickly and easily. So let's break down this question type:

We call these Principle-Strengthen or Principle-Justify.

They almost always have the wording of "which of the following principles, if valid, most justifies ..."

Note the similarity to Strengthen
"which of the following, if true, most strengthens"
and the similarity to Sufficient Assumption
"which of the following, if assumed, allows the conclusion to follow logically"

In all three cases, we want the strongest possible idea that supports the argument.

Although the phrasing of Principle-Justify sounds a lot like Strengthen, it usually acts a lot more like Sufficient Assumption.

With Sufficient Assumption, the correct answer actually proves the argument. It connects the ideas from the premises to the idea in the conclusion with complete certainty.

The correct answer to Principle-Justify often does just that as well (or at least comes pretty darned close --- by contrast, the correct answer to Strengthen questions normally makes the argument more plausible but still falls far short of actually PROVING the conclusion must be true).

In order to prove a conclusion, you need to focus on the specific wording in it.

For example:
"Feeding a dog rat poison invariably kills that dog. Thus, you should not feed a dog rat poison."

What's the missing idea I need to prove the conclusion?

Here's where it pays to think about what wording in the conclusion has not been mentioned otherwise.

Conc: You should not feed a dog rat poison

Normally you'll see that part of the conclusion's wording was mentioned in the premise, but part of it wasn't.

You should not feed a dog rat poison
not mentioned mentioned

Any wording in your conclusion that hasn't been mentioned in the premise NEEDS to be in the correct answer.

The wording in your conclusion that HAS been mentioned will be paraphrased with whatever idea(s) was connected to it in the premise.

What was connected to "feeding a dog rat poison" in the premise?

The idea that "the dog will invariably die."

So the correct principle that would justify this argument would be something like,
"You should not do something that will cause a dog to die."

It would still be correct even if the principle were more far-reaching than we need it to be, such as
"You should not do something that will cause any animal to die."

As long as we know that a dog is an animal (which is certainly in the realm of common sense), this answer would still justify our original conclusion.

Sorry for the long prelude, but again, I want to make sure you follow how I would break down #18.

What is the main conclusion in #18?

This might be the trickiest part of this problem. There are language cues such as "because" (premise) and "so" (conclusion) towards the end of the argument, but they are dealing with making a subsidiary/intermediate conclusion.

The argument really unpacks like this:
"consumers should buy books only from an independent bookstore, not from a chain" [main conc]
why?
"chain bookstores tend to reduce the variety of books available to consumers" [intermediate conc]
why?
"indie bookstores tend to carry a wider variety of books than chain stores do" + "chain stores often threaten the existence of indie stores" [pair of supporting premises]

When we examine our main conclusion for new, unmentioned wording, we see the new wording of "consumers should buy books only from" and the familiar wording of "independent bookstore, not from a [chain]"

So we KNOW we need our correct answer to be a principle about what consumers should/shouldn't buy.

(If you scan the answers looking for that wording, you can get rid of (A) and (C) very quickly. (A) is trying to prove whether chain stores should/shouldn't force indies out of business -- not our conclusion. (C) is trying to prove whether the best interest of the bookselling business is/isn't served by something --- not our conclusion)

However, to make our process easier before we start looking at answers, we should first think about what the premises told us about "indie vs. chain". The big associated idea was that "indie = better variety" and "chain = threatens indies, therefore tending to reduce variety available to consumers".

We know that our correct answer will also include wording related to those ideas.

(B) looks great. It starts off with "consumers should buy books from only", which is how our main conclusion starts ... and then it replaces "independent, not chain" with the related idea of "those bookstores who don't tend to reduce the variety of books available".

Note the fact that everything in (B) maps easily back to wording from the argument. Note further that half of the wording in (B) maps back to wording in the conclusion, and the other half of the wording in (B) maps back to wording from the premises. THIS is the hallmark of correct principle answers. It connects terms from the premises to terms from the conclusion.

(D) matches up okay with the conclusion -- it's talking about whether consumers should/shouldn't make purchases from somewhere. But the other half of (D) doesn't match the premises. We were never told that chain stores DELIBERATELY force indies out of business.

(E) is somewhat tempting. There is wording about where consumers should/shouldn't buy. And there is wording about the diversity (variety) of books. However, there is a HUGE problem: it's telling us to buy books from chain bookstores! The conclusion that we want (E) to help us justify is that consumers should ONLY buy from indies, and NOT from chains. There's no way this answer could help prove our conclusion.

Answers like this go beyond the given argument and try to entice students with something ELSE they think this bookstore owner would be likely to say. We need to know that our task is to prove the given conclusion, not comment on other stuff the author might believe.

I hope this helps. Let me know if I created or failed to resolve any confusion along the way.