#22 - Merle: Usually when I insert a dollar bill into the

[Adam Tyson]

Complete Question Explanation

Parallel Flaw, SN. The correct answer choice is (D).

In this question, the problem is that the author takes their personal experience - what usually happens when they put a dollar bill into the machine - and projects it too far into a conclusion that something must occur. We could reasonably conclude from the evidence that the outlet is usually turned on when the author inserts a bill, but we cannot know anything about what happens with that outlet the rest of the time. Maybe it is off 23 hours a day, and only turned on at lunchtime, and that just happens to be when our author usually hits the change machine?

To categorize this flaw using the common labels (and you never have to do this - it's just something that's helpful to do sometimes), this one would likely be a very rare Over-generalization flaw.

When you are trying to parallel a flaw and you aren't quite sure what the flaw is, you can always fall back on the standard ways of attacking parallel reasoning questions. Match the conclusions, match the premises, match the type of reasoning and the abstract structure. Here, for example, you could eliminate answer A because it has no element of "usually," but is all about "everyone." Answer B doesn't match because it is all about "some," and answer C is about "many," so those should also be easy to cross out. Answer D (the correct answer) and answer E are the only ones that match the "usually" aspect of the argument, by using the word "most," so you're already down to just those two contenders!

From there I would consider the abstract structure, and I would come up with something like "X is usually true in certain cases, but X cannot be true unless Y is also true, so Y is usually true." Answer D matches that, with X being "plot is disturbing," certain cases being "people who have read it," and Y being "vivid imagination." Notice how the conclusion in D matches the simple conclusion of the stimulus - Y must usually be true - while answer E has a more complex, qualified conclusion.

Answer choice (A): This answer begins with a premise that uses "every[one]," which does not match the force of the premise in the stimulus ("usually"). Thus, this answer is incorrect.

Answer choice (B): This answer begins with a premise that uses "some," which does not match the force of the premise in the stimulus ("usually"). Thus, this answer is incorrect.

Answer choice (C): This answer begins with a premise that uses "many," which does not match the force of the premise in the stimulus ("usually"). Thus, this answer is incorrect.

Answer choice (D): This is the correct answer choice, as explained above.

Answer choice (E): In this answer, the conclusion (which uses "most") differs from the conclusion in the stimulus (which uses "must").

[Littletiger1888]

Hi - I've always struggled with questions like this. I can't even see the flaw in the original statement, let alone pick an answer that contains the similar flaw. What's the flaw in this one?

[Adam Tyson]

Hey there Littletiger1888, thanks for the question! I've just gotten through my copy of the November 2019 test and I am excited to start talking about it!

In this question, the problem is that the author takes their personal experience - what usually happens when they put a dollar bill into the machine - and projects it too far. We could reasonably conclude from the evidence that the outlet is usually turned on when the author inserts a bill, but we cannot know anything about what happens with that outlet the rest of the time. Maybe it is off 23 hours a day, and only turned on at lunchtime, and that just happens to be when our author usually hits the change machine?

I think if I had to categorize this flaw using the common labels (and you never have to do this - it's just something that's helpful to do sometimes), I think I would call this one a very rare Over-generalization flaw.

When you are trying to parallel a flaw and you aren't quite sure what the flaw is, you can always fall back on the standard ways of attacking parallel reasoning questions. Match the conclusions, match the premises, match the type of reasoning and the abstract structure. Here, for example, you could eliminate answer A because it has no element of "usually," but is all about "everyone." Answer B doesn't match because it is all about "some," and answer C is about "many," so those should also be easy to cross out. answer D (the correct answer) and answer E are the only ones that match the "usually" aspect of the argument, by using the word "most," so you're already down to just those two contenders!

From there I would consider the abstract structure, and I would come up with something like "X is usually true in certain cases, but X cannot be true unless Y is also true, so Y is usually true." Answer D matches that, with X being "plot is disturbing," certain cases being "people who have read it," and Y being "vivid imagination." Notice how the conclusion in D matches the simple conclusion of the stimulus - Y must usually be true - while answer E has a more complex, qualified conclusion.

[ryanshort8883]

Just for understanding, for (E) to be correct, the stimulus would have to conclude, "Therefore, most electric outlets that are turned on must make a squeaking sound," or something similar, correct?

Thank you!

[Adam Tyson]

I agree, Ryan - that would be a lot closer to what happened in the stimulus. Good work with this confusing mess!

[caseyh123]

Can you explain why "many" is not analogous to "usually"? Is there a reason c is wrong besides that it says many instead of most?

[KelseyWoods]

Hi Casey!

"Many" doesn't have a specific meaning on the LSAT and basically equates to "some" or "at least one." "Most," however, does have a specific meaning which is "more than half." "Usually" means "more than half of the time." Thus, "most" and "usually" are much more similar than "many" and "usually." Check out this blog post for a more in depth analysis of quantity words on the LSAT!: https://blog.powerscore.com/lsat/a-qual ... -the-lsat/.

On a Parallel Reasoning question, the difference between "many" and "usually" would be enough for us to quickly eliminate answer choice (C). But another problem with answer choice (C) is that it seems to be valid reasoning:

P: Many people who read the new horror novel found the plot to be disturbing
P: Everyone who found the plot disturbing has a vivid imagination (Found plot disturbing Vivid imagination)
C: Many people who have read the new horror novel must have vivid imaginations

That conclusion follows from the initial premise and conditional rule. It lacks the overgeneralization element that is in the stimulus and in answer choice (D).

Notice how the conclusions of answer choice (C) and (D) differ:

(C): Many people who have read the new horror novel must have vivid imaginations
(D): Most people must have vivid imaginations

Answer choice (D) makes the jump from "most people who have read the new horror novel" in the premise to "most people" in the conclusion. This better matches the jump that the stimulus makes from "usually when I insert a dollar" to "usually."

Hope this helps!

Best,
Kelsey

[tetsuya0129]

Hi Powerscore,
I picked the correct answer but was being troubled diagramming (A). Could you show the diagram of its conditional logic? Thanks!

[Adam Tyson]

You bet, tetsuya0129!

Premise 1: RN (read novel) PD (plot disturbing)

Premise 2: VI (vivid imagination) PD

Conclusion: RN VI

In that second premise, "anyone" is a sufficient condition indicator.

Notice that this argument is flawed because it treats two things that are each sufficient for the same thing as if they must be in conditional relationship of their own. That's a flaw, but not the same flaw as found in the stimulus, in part because it misses the essential element of "usually" found in the original argument.