LSAT and Law School Admissions Forum

Get expert LSAT preparation and law school admissions advice from PowerScore Test Preparation.

 Administrator
PowerScore Staff
  • PowerScore Staff
  • Posts: 8917
  • Joined: Feb 02, 2011
|
#33153
Complete Question Explanation

Flaw in the Reasoning—FL. The correct answer choice is (D)

There are two areas of difficulty in this question. First, the question stem is worded confusingly, masking that this is a Parallel Reasoning, Flaw in the Reasoning question. Next, there are two logical flaws in the stimulus to discover and consider in reviewing the answer choices, including a second appearance of Formal Logic in this section.

The company president predicts that the Vegetaste Burger will probably be very successful. The president backs up this prediction with evidence that almost every really successful product introduced in the last ten years has been launched by a massive television advertising campaign. Since the company will be using a massive television advertising campaign to introduce the Vegetaste Burger, the president concludes the Vegetaste Burger will probably be very successful.

The president’s argument is flawed because it commits a time-shift error, though a tempered one. A time-shift error involves assuming that conditions remain constant over time, and that what was the case in the past will be the case in the present or in the future. Often, the conclusion that results from a time-shift error is definitive. Here, the conclusion is probabilistic, but is a time-shift error nonetheless. Just because almost every really successful product introduced in the last ten years has been launched by a massive television advertising campaign does not provide support for the conclusion that the Vegetaste Burger will probably be very successful because of its anticipated, massive television advertising campaign.

Perhaps there is something about the Vegetaste Burger that makes it particularly unsuited for launch by a television advertising campaign. Maybe an important market segment no longer watches television, but rather gets its entertainment online. There could be any number of reasons why what was true in the past will not be true in the future. It is not necessary that you identify these potential reasons, so long as you recognize that it is improper to assume that conditions will remain constant over time.

The second error is one of Formal Logic, in which the president improperly reverses the relationship provided in the first sentence of the stimulus: almost every really successful product introduced in the last ten years has been launched by a massive television advertising campaign. This statement is diagrammed below. Note that when you diagram a relationship involving the term “almost,” you symbolize that term as “most.” This is because the word “most” can be defined as “a majority, possibly all.”

RSP = really successful product introduced in the last ten years
MTAC = launched by a massive television advertising campaign
  • RSP ..... :most: ..... MTAC
After establishing this relationship, the president then concludes that since the Vegetaste Burger is being launched by a massive television advertising campaign, it will probably be very successful as well. Essentially, the president is saying that almost every product launched by a massive television advertising campaign is really successful, which you would diagram as:
  • MTAC ..... :most: ..... RSP
This inference is unsupported, because the “most” relationship in Formal Logic is non-reversible, meaning the relationship between the two variables does not have exactly the same meaning regardless of which “side” of the relationship is the starting point of the analysis. In this case, beginning the analysis with the MTAC term produces only this relationship: some products launched by a massive television advertising campaign are really successful:
  • MTAC ..... :some: ..... RSP
A proper inference from this relationship would be that the Vegetaste Burger might be very successful given its launch by a massive television advertising campaign. This conclusion would avoid not only the Formal Logic error, but also the time-shift error. However, the president’s conclusion commits both errors.

To quickly attack the answer choices, first eliminate any answer choice that does not have a probabilistic conclusion that predicts what will occur in the future. If the conclusion is not predictive, then the argument will not have committed the same time-shift error. If the conclusion is not probabilistic, then the argument will not have committed the same reversal of Formal Logic.

Answer choice (A): This answer choice is incorrect because its conclusion, that the president of Corbin Corporation has an office that is not in Corbin’s headquarters building, is a definitive statement of a current state of affairs, rather than a probabilistic prediction about what will occur in the future.

Answer choice (B): The conclusion to this answer choice, that Donna has at least ten years of experience as a computer programmer, is also a definitive statement of a current state of affairs. This answer choice is more attractive than answer choice (A), however, since its final premise is a probabilistic prediction about what will occur in the future.

Answer choice (C): This answer choice is incorrect, because its conclusion, that almost all of Acme’s employees oppose the pending merger with Barrington Corporation, is not a prediction regarding the future, despite the pending status of the merger.

Answer choice (D): This is the correct answer choice. As with the argument in the stimulus, the conclusion to this argument results from two reasoning flaws. First, the argument commits a time- shift error when it predicts the likelihood of Robinson being appointed as president based on what has occurred in the past. Second, the conclusion results from an improper reversal of the evidence that almost every one of Sifton’s previous presidents had a Ph.D.

Answer choice (E): The argument in this answer choice commits only the time shift error described above, when it concludes that the novel will probably earn a profit for its publisher based on the past performance of prior novels published by Peninsula Press.
 maximbasu
  • Posts: 59
  • Joined: May 19, 2016
|
#25138
Hello,
I chose E as the correct answer while the correct answer was D.

I diagrammed the reasoning in the stimulus like this:

successful --> TV campaign
TV campaign --> successful

There is a Mistaken Reversal.

I diagrammed D as:

Robinson --> appointed president --> PHD
Robinson --> PHD

How would you diagram E as?

Thank you, Maxim.
 Nikki Siclunov
PowerScore Staff
  • PowerScore Staff
  • Posts: 1362
  • Joined: Aug 02, 2011
|
#25173
Hi Maxim,

You're correct in that we're looking for a Mistaken Reversal, but with a probabilistic twist in the conclusion:
  • Premise: ..... Successful product launch :most: TV ad
    Premise: ..... TV ad Vegetaste
    Concl.: ..... Successful product launch Vegetaste (most likely)
This is the same flawed line of reasoning that we see in answer choice (D):
  • Premise: ..... Sifton president :most: PhD
    Premise: ..... PhD Robinson
    Concl.: ..... Sifton president Robinson (most likely)
Answer choice (E) can be diagrammed as:
  • Premise: ..... Peninsula :most: Profitable novels
    Premise: ..... Safekeeping Peninsula
    Concl.: ..... Safekeeping :most: Profitable (most likely)
The reasoning in answer choice (E) is logically valid, which is not what we're looking for.

Hope this helps!
 emilysnoddon
  • Posts: 64
  • Joined: Apr 22, 2016
|
#25740
How is answer choice B different from answer choice C in this question?
 Nikki Siclunov
PowerScore Staff
  • PowerScore Staff
  • Posts: 1362
  • Joined: Aug 02, 2011
|
#25855
Emily,

To clarify, neither (B) nor (C) is a correct answer to this question. The correct answer choice is (D).

Answer choice (B): The conclusion to this answer choice, that Donna has at least ten years of
experience as a computer programmer, is a definitive statement of a current state of affairs.
Since we're looking for a probabilistic conclusion, this answer choice is incorrect.

Answer choice (C): This answer choice is incorrect, because its conclusion (almost all of Acme’s
employees oppose the pending merger with Barrington Corporation), is not a prediction about the
future.

The correct answer choice is explained above.

Thanks!
 awilt
  • Posts: 6
  • Joined: Oct 21, 2017
|
#40834
I am so thrown by this question! I chose E for the time shift and probability. I don't see how E is any different from D.
 nicholaspavic
PowerScore Staff
  • PowerScore Staff
  • Posts: 271
  • Joined: Jun 12, 2017
|
#40877
Hi awilt,

I think Nikki does a good job of explaining that above, but let's look at it from this standpoint. If it is published by Peninsula, then most of those published works are profitable. Safekkeping is being published by Peninsula, so it will probably earn a profit. There's actually nothing wrong logically with that prediction of probability in Answer Option (E) because we know that it's "most" (>50%). So it's not making the same mistake in formal logic that the stimulus makes which is a Mistaken Reversal in the second and third sentences which declares that V will most likely be succesful based on the conditional logic in the first sentence. Therefore, Answer Option (E) did NOT make the same mistake and is incorrect.

Thanks for the great question and I hope this helps!
 emekj
  • Posts: 6
  • Joined: May 02, 2018
|
#49318
Hi!
I am having trouble seeing the difference between answers B and C. I don't see how the phrase "Diana has 10 yrs experience" in answer B is any more of a description of current affairs than the phrase "Robert has a PHD" in D. I don't understand why that phrase from B makes the answer incorrect.
User avatar
 Jonathan Evans
PowerScore Staff
  • PowerScore Staff
  • Posts: 726
  • Joined: Jun 09, 2016
|
#49502
Hi, EmekJ,

Good question! Let's do a quick description of the stimulus to create a tool we can use to match up with the answers:
  • Almost every successful product in the past has had a certain characteristic.
  • This new product has this characteristic.
  • Conclusion: This new product will probably be successful.
What's the problem here? There are two issues:
  1. We do not know whether the characteristic was causally connected to the product's success. It could have been a coincidence. (In other words, we don't know that the ad campaign had anything to do with the success.)
  2. We have a ceteris paribus (time shift) fallacy. Just because things were a certain way in the past doesn't mean that things will continue to be this way in the present.
Now let's take a look at answer choices (B) and (D):
  • B.
    • Almost everyone working for a company has a characteristic.
    • Donna will probably be hired by this company.
    • Conclusion: Donna has this characteristic.
    The issue with (B) is that the conclusion is not the correct match. For a match, we should conclude that Donna will probably be hired, not that she has ten years experience.

    D.
    • Almost every president has had a certain characteristic.
    • Robinson has this characteristic.
    • Conclusion: Robinson will probably be appointed president.
    This answer choice syncs up with the structure of the stimulus.
I've color-coded the matching statements. I hope this helps!

Get the most out of your LSAT Prep Plus subscription.

Analyze and track your performance with our Testing and Analytics Package.