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#36723
Complete Question Explanation

Parallel Reasoning, SN. The correct answer choice is (C)

The above-average difficulty level of this question is primarily due to the confusing approach taken
in creating the five answer choices, rather than the stimulus itself. The stimulus contains an argument
with a relatively simple structure, as described below. The answer choices, however, test your ability
to compare and contrast the abstract relationships that underlie each argument. It does not help
that all five of them deal with the same topic, which—though irrelevant to the structure of each
argument—makes your task even more challenging.

It may be helpful to diagram the argument contained in the stimulus as if it contained conditional
reasoning. However, keep in mind that the relationships in each premise are less than absolute, due
to the use of such phrases as “typically” and “tend to.” Nevertheless, since our primary objective is to
understand the logical structure of the argument as clearly as possible, such a conditional approach
would be justified, albeit with a caveat.

The first sentence indicates that cities with healthy economies typically have plenty of job openings:
  • HE = Healthy economies
    JOB = Job openings

    S ..... ..... N
    HE :arrow: tend JOB
The first clause of the second sentence states that cities with high-technology businesses also tend to
have healthy economies:
  • Hi-Tech = Cities with high-technology businesses

    S ..... ..... N
    Hi-Tech t :arrow: end HE
You may notice that the two premises, when combined, produce the following chain:
  • High-Tech :arrow: tend HE :arrow: tend JOB
On the basis of this information, the author concludes that those in search of jobs should move to
a city with high-technology businesses. In other words, those in search of the necessary condition
should seek an area where the sufficient condition occurs. Note that this is not a Mistaken Reversal;
the author does not suggest that the necessary makes the sufficient condition occur, but rather that
looking for the sufficient condition is a viable approach if you want find the necessary condition.

Our job is to parallel the reasoning contained in the stimulus. To do that, we must parallel the
conclusion as well as the premises, making sure to “match” the language of both. First, we need to
find an answer choice in which the conclusion that uses the language of a recommendation (words
such as “should,” “must,” “ought to,” etc.) and suggests that seeking a sufficient condition is an
advisable avenue if one seeks the occurrence of the necessary condition. On the premise side, the
correct answer choice will contain the two premises that can be combined, and whose wording
makes make the conditional relationship between them less than absolute.

Because the argument is not flawed, the question stem does not indicate the presence of a logical
flaw.

Answer choice (A): This answer choice can be diagrammed as follows:
  • Premise (1): Older antiques :arrow: Usually most valuable antiques
    Premise (2): Antique dealers :arrow: Authenticate age
    Conclusion: Buy most valuable antiques :arrow: Antique dealers
You should notice that there is no “link” between the first and the second premise in this answer
choice. Indeed, just because antique dealers authenticate the age of the antiques they sell, that does
not necessarily mean that they sell older antiques. Since the conclusion does not follow from the
premises, this answer choice is incorrect.

Answer choice (B): This answer choice, when re-worded, has the following argument structure:
  • Premise (1): The most valuable antiques are those whose age has been authenticated.
    Premise (2): Dealers who authenticate the age of the antiques they sell have plenty of
    antiques for sale.
    Conclusion: Buyers of valuable antiques should purchase them from antique dealers.
The conclusion in this argument does not take the same form as that in the stimulus. Also, having
“plenty” of antiques for sale does not automatically make them the most valuable. Do not get
distracted by the repetition of the word “plenty,” which also appears in the stimulus—this similarity
is irrelevant to the logical structure of the argument. Lastly, just because an antique collector is
searching for valuable antiques, that does not mean she is in search for the most valuable antiques.

Since either of these inconsistencies would be sufficient to eliminate this answer choice from
consideration, no conditional diagramming is necessary to prove it wrong.

Answer choice (C): This is the correct answer choice. The argument has the following structure:
  • Premise (1): Age authenticated :arrow: tend Valuable antiques
    Premise (2): Antique dealers :arrow: generally Age authenticated
    Conclusion: Valuable antiques :arrow: Antique dealers
As in the stimulus, the two premises can be combined to form the following chain:
  • Antique dealers :arrow: generally Age authenticated :arrow: tend Valuable antiques
On that basis, the author concludes that collectors seeking valuable antiques should be purchase
their antiques from antique dealers. Since antique dealers do sell valuable antiques, the author’s
conclusion is reasonable.

Some students object that the wording in this answer choice is not identical to that in the stimulus.
But, “generally” and “tend” have the same logical force, and thus there is no problem with the
wording; synonymous words and phrases are acceptable because you attempting to parallel the
structure, not the exact wording.

Answer choice (D): This answer choice fails to Double the Conclusion and can easily be ruled out.
The conclusion in this answer choice does not contain a recommendation (“should”), but rather a
statement of fact (“most antique collectors who want antiques that are valuable tend to purchase their
antiques from antique dealers”), which is sufficiently different to make this answer incorrect.

Answer choice (E): Hopefully, you were able to eliminate this answer choice rather quickly. The first
premise indicates that many antiques increase in value once they have had their ages authenticated
by antique dealers; however, this information is irrelevant to the remainder of the argument and
cannot be combined with the second premise. Because the second premise provides independent
grounds for the conclusion of the argument, the pattern of reasoning contained in this answer choice
deviates significantly from that in the stimulus.
 abares
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#22867
Can someone explain this question and the steps to determine how to breakdown stimulus to compare to answers?

Thanks!
Annie
 Adam Tyson
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#22870
Thanks for the question, Annie! There are a number of special approaches we can take with this question type, which is Parallel Reasoning. Overall, you want to parallel all the key elements—do the conclusions use the same type of language, with the same degree of certainty or probability? If the argument seems valid, make sure the answer you pick is also valid. Consider the abstract structure of the argument and compare that to the structure of the answer choices. You don't need to worry about the topic or the order of presentation.

Now, with some of those elements in mind, what do we have? In the premises, we have a "typically" relationship in the first sentence, and then a "tends to" (which is the same as "most") in the second, followed by a conclusion featuring "should." Now, we don't need the same order of presentation in the correct answer, but we do need the same type of pieces with roughly the same force (Typically-Most-Should). And keep in mind that we don't need the same exact words in each premise/conclusion, but we need the same force of language or general idea. That said, let's look at what we have in a Contender/Loser sweep using just basic language elements:

  • Answer choice (A): Contender.

    Answer choice (B): Loser. The second premise features language ("are") that is stronger than that in either premise in the stimulus.

    Answer choice (C): Contender.

    Answer choice (D): Loser. The second premise features language ("always") that is stronger than that in either premise in the stimulus, and the conclusion features a qualifier ("Most") that doesn't match the stimulus.

    Answer choice (E): Loser. This one is more debatable, but the first premise is suspect. "Many antiques increase" is not the same as "typically" or "most" (both of which imply a majority; "many" doesn't imply a majority). If I went through all the other answers and didn't find an answer I liked, then I'd come back to this, but on the surface this is sufficiently different from the stimulus to knock out.

So, in our first sweep through the answers, we knocked out two of them fairly easily, and the third (E) was a bit more debatable. But the remaining two looked pretty similar. So, let's look at the element we didn't focus on: the actual pieces of the argument and how they relate. Reordered, the stimulus appears as:

  • Premise: City w/ High Tech --tend to--> Healthy Economy

    Premise: Healthy Economy --typically--> Plenty Job

    Conclusion: So, if want Job, then City High Tech
The author sets up a chain of sorts, and says that if you are a job seeker, then go find the sufficient condition that tends to create the result of plenty of jobs. If we were to think about this conditionally, it's like A :arrow: B :arrow: C, and if you need C, then go to A. That's a very rough analysis, but should be good enough for our purposes. With that in mind, let's go back to those two Contenders. We want an answer that has three elements that can be connected in a chain (like A :arrow: B :arrow: C) and then a conclusion that says to get the last term you should go to the first term (again, this is a rough approximation).

  • Answer choice (A):

    ..... Premise: Older Antique --usually--> Most Valuable

    ..... Premise: Antique Dealer --generally--> Authenticate Age

    Stop! right here you can see that the two premises have four elements that don't connect; this is different than the stimulus. It's a Loser.


    Answer choice (C): This is the correct answer, and note how it parallels the language of the stimulus:


    ..... Premise: "tend to"

    ..... Premise: "generally"

    ..... Conclusion: "should"


    The order of the two premises is different, but that has no significance. When seen from a structural standpoint, answer choice (C) matches the stimulus perfectly:


    ..... Premise: Antique Dealer --generally--> Age Authenticated

    ..... Premise: Age Authenticated --typically--> Valuable

    ..... Conclusion: So, if want Valuable, then Antique Dealer

Once you get into the Parallel Reasoning lesson, questions like this get a LOT easier. Using the right techniques (and with practice you will get quite fast at performing the analysis above), we really only had to focus on two answer choices, and as we saw, one of them turned out to be correct. That's how we can use proper techniques to power our way through what is a generally difficult and time-consuming question type.

Please let me know if that helps. Thanks!
 abares
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#23082
Yes, thank you Adam!

Best,
Annie
 jrc3813
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#41481
How should you diagram the statement "the most valuable antiques are those that have had there age authenticated"?

Would it be most valuable :arrow: age authenticated? Something about the "are those that have" part makes it seem biconditional.
 nicholaspavic
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#42093
Hi jrc,

I agree with your diagramming of (B) and I do not think it should be expressed with the double arrow. Why? Well because age authenticated is not a sufficient to make it a valuable antique. In other words, that valuable antique has that authentication but the authentication does not always have the antique. Thanks for the great question and I hope this helps!
 kenlars5
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  • Joined: Oct 27, 2020
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#82810
Hi there,

So I got this question right but when reviewing my test and specifically this question the explanation and approach provided here was completely different than mine. Just looking for some clarification on whether my approach was sound or if I just got lucky.

1. I approached this question as a formal logic question and diagrammed accordingly:
P1: HE :most: JO
P2: Hi-Tech :most: HE
Conclusion: You get from INCORRECTLY combining the two: Hi-Tech :most: HE :most: JO and assuming that if you are in search of the "necessary condition" then you should satisfy the sufficient condition. After reading the argument I immediately thought that the argument was flawed and despite the question stem not identifying the flaw I know its possible that it doesn't always.

2. My pre-phrase was that the answer is going to be flawed and its going to incorrectly connect 2 "most" statements: A :most: B :most: C and then conclude that if you are looking for C you SHOULD satisfy A.

A) The first two premises don't connect so no.
B) The second premise isn't a "most" - it said thats the "most valuable antiques are those that have had their ages authenticated" = Most valuable :arrow: Age authenticated; so no get rid of it.
C) Yes
P1: antiques whose age is authenticated :most: valuable
P2: Antique dealers :most: carry antiques who age is authenticated
COMBINE: Antique dealers :most: carry antiques whose age is authenticated :most: valuable
Conclusion: if you are looking for valuable antiques you should buy from antique dealers - matches perfect
D) No- conclusion doesn't match - doesn't recommend anything - needs to say "should" or a synonym
E) No- first word says "many" and many doesn't necessarily equal "most"

Thank you and I look forward to hearing back!

Kendra
 Adam Tyson
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#83701
Great job, Kendra, your approach is fantastic! We haven't talked about the flawed nature of this stimulus so far in this thread, but you are absolutely right to take note of it, and your breakdown using the tools of Formal Logic is spot on. Well done!

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