#25 - Some visitors to the park engage in practices that

[PhilD]

I see how answer choice C is correct, but how is answer choice B incorrect? When I diagram answer choice B, I get the same structure as the stimulus.

Thanks!

[Alex Lucas]

Hi Phil!

This is a tricky question, and eliminating B requires careful attention to how the statements are linked in the stimulus.

P1: Some visitors harm animals.
P2: Harm animals --> no knowledge
C: Some visitors have no knowledge.

Abstracting these terms, you get a structure that looks like:

Some A are B
B --> not C
Some A are not C

Answer choice B is structured a little differently.

P1: Some petition-signers were supporters. (Some A were B)
P2: Petition-signer --> denounced. (A --> C)
C: Some denounced were supporters. (Some C were B)

While this statement is valid, it doesn't mirror the structure of the stimulus. Let me know if you have any other questions.

[PhilD]

Thanks a lot!

[Jkjones3789]

Hello, for this Parallel question I tried to parallel the premises and conclusion with the degree of certainty in the conclusion along with the use of the some and no one along with a some. I felt like they were all saying the same thing and the must wasn't present it any of them so I guess maybe I should have used the Test of Abstraction. Could you please explain this question to me and diagram it out if necessary or applicable. Thank you

[Nikki Siclunov]

Hi Jkjones3789,

The argument in the stimulus contains formal logic, which is explained in one of the Supplemental Virtual Modules on the Online Student Center (Lesson 8).

As always, Parallel Reasoning questions require that we understand the argument from a structural standpoint. The first premise states that some visitors harm animals:

Premise: Visitors Harm animals

According to the second premise, however, no one would knowingly harm animals, i.e. if you know that your actions are causing harm, you wouldn't engage in them. By the contrapositive, if you are harming animals, you can't possibly know that you're doing so (generally speaking, a statement in the form of "No A's are B's" can be represented as A B):

Premise: Harm animals Know

The conclusion then states that some visitors do not know that they are harming the animals:

Conclusion: Visitors NOT Know

This argument is logically valid. Whenever you notice conditional reasoning or formal logic, it is important to understand precisely the structure you need to parallel. In this instance, the structure can be understood as follows:

Premise: A B
Premise: B C
Conclusion: A NOT C

We can use the Premise Test to eliminate answer choices (A), (B), (D) and (E), because their premises all use an A B construction, using sufficient indicators such as "everyone" - answer choices (A) and (B) - and "all" - answer choices (D) and (E). We are left with answer choice (C), which we can diagram in order to confirm that it contains the same structure of argumentation:

Premise: Polled Outside city
Premise: Outside city Vote
Conclusion: Polled Vote

Thus, the structure is identical to the original argument, proving that answer choice (C) is correct.

In Parallel Reasoning questions, structure is always key. Sometimes, however, we can take shortcuts (such as the Premise and Conclusion tests) to quickly eliminate answer choices that deviate from the language used in the original premises and/or conclusion. That said, always make sure to verify that the answer you choose matches the logical structure of the argument contained in the stimulus.

Hope this helps!

[ashpine17]

Does E have the none? CC--->O?

[Adam Tyson]

I wouldn't view it that way, ashpine, although "in favor" and "opposed" are polar opposites (as opposed to logical opposites.)

To make E work, we would need the "some" relationship in the conclusion to go the other way: Some members of the Liberal Party are not on the city council. E is not valid, because it's possible that all the members of the city council are Liberals. Also, is "Liberals" the same thing as "members of the Liberal Party"? That's not entirely clear to me, although the capitalization of Liberals suggests that they meant it to be the same.

[Cflores17]

Hi Phil!

This is a tricky question, and eliminating B requires careful attention to how the statements are linked in the stimulus.

P1: Some visitors harm animals.
P2: Harm animals --> no knowledge
C: Some visitors have no knowledge.

Abstracting these terms, you get a structure that looks like:

Some A are B
B --> not C
Some A are not C

Answer choice B is structured a little differently.

P1: Some petition-signers were supporters. (Some A were B)
P2: Petition-signer --> denounced. (A --> C)
C: Some denounced were supporters. (Some C were B)

While this statement is valid, it doesn't mirror the structure of the stimulus. Let me know if you have any other questions.

Wouldnt it just be easier to go by the abstract form (SOME-NONE-SOME)?

Conditonality makes this problem so much more difficult then it needs to be. Feedback is appreciated.

[Amber Thomas]

Hi CFlores!

We can summarize the premises and conclusion as follows:

Some visitors harm animals
Nobody who knew their practices harmed animals would do those practices
Therefore, some visitors must not know their practices harm animals

This isn't a conditional reasoning question, however, the diagrams you may make might look somewhat similar. Ultimately, what you are looking for are whether or not the terms that define quantity (some, none, some) match up and are used in the same way as in the answer choices.

I hope this helps!