## Preptest 43, LR questions

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Origin

Posts: 17
Joined: Wed Jul 04, 2007 7:56 pm
I'll take the second one since I don't know what you're asking in the first one.

A trick/shortcut: In an assumption question like this, when there is something in the premise that does NOT appear in the conclusion, that premise will likely be in the answer choice.

In this case, the stimulus says "Since the acceptance of criticism requires that one respond positively to it, students are more likely to learn from criticism by humans than from criticism by computers."

It it making the jump from the first part (before the comma) to the second part (after the comma) without actually linking those.

If A is assumed:

P1: Negative Criticism By Computer Programs -----> ~Respond Positively

P2: Accept Criticism ------> Respond Positively

P3 (choice A): MLTL -----> Accept Criticism

C: More likely to learn -----> ~C

Now combine the premises:

P3 ----> P2 ----> Contrapositive of P1

Does that prove the conclusion?

MLTL -----> Accept Criticism -----> Respond Positively ----> ~C

If they are more likely to learn from criticism they accept criticism and thus respond positively. Therefore, the criticism is not from a computer. Since the stimulus only gives Humans as an alternative to computer programs, choice A would make the conclusion correct.

The Kid

Posts: 52
Joined: Sun Nov 01, 2009 2:33 pm

### Re: Preptest 43, LR questions

I know it's an old topic... anyway, I still can't get this question clear. I did exactly the same as Origin but, in my humble opinion, there's a major flaw in his reasoning: it simply equates "less likely to respond positively" (premisse 1) with the negation of "respond positively".

I guess the only way of perfectly diagramming the reasoning is through formal logic and the operator "most". So, the first premisse should be transcribed as:

criticism by computer --- (MOST) ---> -(respond positively)

However, there's no answer to the question if done that way.

I would really appreciate to hear what you think.

dynomite

Posts: 143
Joined: Sat Jan 30, 2010 6:58 pm

### Re: Preptest 43, LR questions

The Kid wrote:However, there's no answer to the question if done that way. I would really appreciate to hear what you think.
You're confusing yourself. This isn't about "most" relationships. The stimulus is asking about the assumption -- the gap in logic -- in the argument... which is that accepting something affects learning from it.

If there's no relationship, than whether someone accepts something is irrelevant to their ability to learn from it.

Edit: Also, to the thread starter -- what you've posted is illegal. Go back to the index of this forum and read the thread in all caps about posting full questions.

The Kid

Posts: 52
Joined: Sun Nov 01, 2009 2:33 pm

### Re: Preptest 43, LR questions

dynomite wrote:You're confusing yourself. This isn't about "most" relationships.
It is. If the question stem states that "when students receive negative criticism generated by computer programs, they are less likely to respond positively...", we can't conclude as Origin did (and I, too) that

Negative Criticism By Computer Programs -----> ~Respond Positively

Rather, MOST students that receive criticism etc. don't respond positively and the diagram I proposed should be used instead.

(R: I hope my posts haven't broken any of the forum rules.)

dynomite

Posts: 143
Joined: Sat Jan 30, 2010 6:58 pm

### Re: Preptest 43, LR questions

The Kid wrote:the diagram I proposed should be used instead
The key to this question -- as I see it -- is to stop and realize you aren't evaluating the argument as a whole. That's not what the question is asking you to do. "Which assumption is necessary" means an assumption whose negation would ruin the argument.

So just glance at it. Where does the argument seem to equate between two different terms that have no apparent link?

A relationship between acceptance and learning is required. If there is none, then the two terms in question do not affect each other, and the argument is logically invalid.

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chewdak

Posts: 106
Joined: Fri Apr 03, 2009 5:54 pm

### Re: Preptest 43, LR questions

dynomite wrote: A relationship between acceptance and learning is required.
That's right.
There is a jump from "acceptance of criticism" to "more likely to learn".
An assumption which bridges this gap is what we are looking for.

The Kid

Posts: 52
Joined: Sun Nov 01, 2009 2:33 pm

### Re: Preptest 43, LR questions

Dynomite and Chewdak, you both are right in saying that a relationship between "learn" and "acceptance" must be sought. This is what Origin called shortcut. But, to put it in logical reasoning terms, such relationship is necessary, not sufficient. That is, in order to PROVE the correct answer we need to build the chain of conditional reasoning (which Origin did) and see where alternative "a" fits. That's where the trouble begins. The chain in Origins' post would only be right IF we considered that "less likely to respond positively" means the same as "not respond positively". I simply can't agree with that.