what does this sentence mean? Forum

[ahri]

for a flaw question there was this answer choice....
The evidence for a claim has not been undermined unless that evidence has been proven false.

it's supposed to mean: no evidence means its false.

[cc.celina]

I'm not sure what you're asking, but those two statements are not equivalent.

The first states:
Evidence for a claim undermined --> evidence proven false

The second states:
No evidence --> claim is false

The first is making a statement about in which conditions evidence may be undermined, and the second is making a statement about the truth of the claim itself. Just because some evidence has been undermined doesn't mean that the claim is false.

[Nova]

Also,
When you see "unless", you can reverse the statement and negate the sufficent condition to make it easier to read.

If the evidence has not been proven false, then the evidence for a claim has not been undermined

~PF -> ~U
=
U -> PF

[ahri]

I thought the same thing but here's some context (i might have missed something):

Faden: Most of our exercise machines are still in use after one year. A recent survey of our customers shows this.
Greenwall: But many of those customers could easily be lying because they are too embarrassed to admit that don't exercise anymore.
Faden: You have no way of showing that customers were lying. Your objection is absurd.

Which one of the following most accurately describes a flaw in the reasoning above?

Correct answer choice: Faden presumes, without providing justification, that the evidence for a claim has not been undermined unless that evidence has been proven false.

[cc.celina]

I suppose in this case, it is because Fadden immediately dismisses Greenwall's criticism by saying "You can't prove that, so it's not true!" without taking into account that Greenwall has suggested a reasonable possibility of inaccuracy in the survey. So what Fadden is implying is that the evidence -- aka, the survey of the customers -- is 100% valid (can't be undermined) unless Greenwall has proof, rather than just a strong suspicion, that customers lied.

Still not sure what the statement "no evidence means it's false" has to do with this question, but that's my take on it.

[Fianna13]

which Pt is this question from?

[cc.celina]

which Pt is this question from?

Superprep B as far as google tells me.

[ahri]

@fianna: preptest C section 3 question 19

@cc.celina: thanks for the explanation. i guess what tripped me up is i kept looking for him to address more explicitly about the issue of no evidence doesnt mean it's false.

[CR2012]

A helpful hint with ''unless'' sentences is to negate what would be the modifier and then proceed with the original form of what would be modified.

Example:

The evidence for a claim has not been undermined unless that evidence has been proven false.

=

If the evidence has not been proven false, then the claim has not been undermined.

A very mechanical way of getting through these quickly and painlessly.

CR

[TopHatToad]

All the advice about "unless" and flipping your conditional is correct, so if that helps you frame the answer choice, there ya go.

If you want to think about it linguistically, look at it this way:

Fadden claims that his assertion (working machines) still holds up 100%, because there is no hard evidence to the controversy. However, what Greenwall suggested is a reasonable possibility, and therefore could be true. If this were a Weaken question, G's claim would definitely weaken F's case, would it not? That's the flaw that this answer choice points to-- F dismisses a reasonable alternative to his claim on the basis that it hasn't been conclusively proven.

Still not sure what the statement "no evidence means it's false" has to do with this question, but that's my take on it.

That wording is better understood with the symbolic logic. ~PF --> ~U
Fadden assumes the above conditional, that if his claim isn't 100% refuted, then it's still perfectly good. In reality, however, enough doubt can be cast on his claim so that it's unlikely, which does in fact undermine it.

[TylerJonesMPLS]

PT C Section 3 question 19

To fill in ahri’s formulation: “No evidence means it’s false” = Since Greenwall can’t produce evidence that many of the customers were lying out of embarrassment, it must be false that many of the customers were lying out of embarrassment.

To fill in the AC formulation of the flaw, “The evidence for a claim has not been undermined unless that evidence has been proved false.”

The claim is Fadden’s claim that exercise machines are still in use after a year. The evidence for Fadden’s claim is a customer survey. Greenwald offers a consideration that might undermine the evidence of the survey, namely that customers who took the survey may be lying out of embarrassment. Fadden replies that since Greenwall cannot prove that the customers were lying, he has not undermined Fadden’s claim at all.

(My interpretation above is the same as cc.celina’s I think.)

TopHatToad and CR2012 are right about unless, as far as I can see.

“Unless” is tricky. I know practicing lawyers who don’t know what “unless” means.

Unless is the logical equivalent of P and/or Q ; ~P > Q ; ~Q > P

So there are three possible logically equivalent ways of restating the correct AC, and you can pick whichever one you are most comfortable with.

You could say:
1) Either the evidence for a claim has not been undermined, OR that evidence has been proved false.
2) If the evidence for a claim has been undermined, then that evidence has been proved false.
3) If the evidence has not been proved false, the evidence for a claim has not been undermined.

[polobull]

for a flaw question there was this answer choice....
The evidence for a claim has not been undermined unless that evidence has been proven false.

it's supposed to mean: no evidence means its false.

The flaw outlined in that answer choice is the creation of a false dichotomy. It is saying that a position cannot be weakened without being totally destroyed.

[ahri]

for a flaw question there was this answer choice....
The evidence for a claim has not been undermined unless that evidence has been proven false.

it's supposed to mean: no evidence means its false.

The flaw outlined in that answer choice is the creation of a false dichotomy. It is saying that a position cannot be weakened without being totally destroyed.

thanks for pointing out the rule for misuse of evidence. I just don't understand why my book said the evidence misconception used was the no evidence proves something is false.

On another note, i was wondering have you guys seen other problems like this that are more circumvent with their flaw answers. What i mean is since i have started studying i notice most of the flaw problems are pretty upfront. Taking this problem for example, one would think the answer would point out fadden's flaw of thinking that greenwall's evidence can't be proved so it is false because his second part explicitly points to this flaw of reasoning.

However, instead the test makers go with an implicit answer that points to a flaw which emphasizes fadden unable to recognize that it isn't necessary to prove his evidence wrong to weaken his position.

His response (2nd part), which where the flaw lies, doesn't take issue with the idea that "only by proving his evidence wrong can his argument be weakened". His response attacks greenwall's evidence, and doesn't mention the idea that proving my evidence wrong is necessary to undermine my argument. His response doesn't seem to be concerned with the function of greenwall's evidence ( does it complete the conditional statement: to undermine my argument one must prove my evidence false). And his response seems to be more concerned if Greenwall's evidence is true.

[cc.celina]

Greenwall does not provide any evidence; he only suggests that Fadden's evidence may be methodically flawed. Fadden doesn't give any reason that Greenwall's suggestion might be false, except: "You have no way of proving that my study is flawed." He's not attacking the truth of Greenwall's assertion from any reasonable grounds, and he dismisses Greenwall's objection as "absurd" because it does not have concrete evidence to back it up.

Greenwall may never have concrete evidence to back up his accusation, but it DOES clearly weaken Fadden's conclusion, because it calls into question a necessary assumption that Fadden makes: that the customers are being honest.

Fadden ignores the fact that it weakens his argument and focuses on the fact that Greenwall's evidence-less accusation is unprovable. Therefore, he presumes that his own evidence (the survey of the customers) is still rock solid, even though Greenwall has given a good reason to be skeptical of it.

So I think your interpretation is coming from the fact that you're looking at Greenwall's statement as evidence. It's not. It's just a methodological flaw in the study that needs to be disproven for the study to be considered valid. It doesn't need to be true to weaken the argument.

[polobull]

Greenwall does not provide any evidence; he only suggests that Fadden's evidence may be methodically flawed. Fadden doesn't give any reason that Greenwall's suggestion might be false, except: "You have no way of proving that my study is flawed." He's not attacking the truth of Greenwall's assertion from any reasonable grounds, and he dismisses Greenwall's objection as "absurd" because it does not have concrete evidence to back it up.

Greenwall may never have concrete evidence to back up his accusation, but it DOES clearly weaken Fadden's conclusion, because it calls into question a necessary assumption that Fadden makes: that the customers are being honest.

Fadden ignores the fact that it weakens his argument and focuses on the fact that Greenwall's evidence-less accusation is unprovable. Therefore, he presumes that his own evidence (the survey of the customers) is still rock solid, even though Greenwall has given a good reason to be skeptical of it.

So I think your interpretation is coming from the fact that you're looking at Greenwall's statement as evidence. It's not. It's just a methodological flaw in the study that needs to be disproven for the study to be considered valid. It doesn't need to be true to weaken the argument.

good stuff

[polobull]

The flaw is two-fold? If I'm understanding this correctly Fadden is using a flawed premise (the lack of evidence as evidence of falsity) to make a flawed argument (that his argument cannot be undermined without being destroyed).

Fadden: You have no way of showing that customers were lying (flaw one). Your objection is absurd (flaw two).

That seems complicated.

[cc.celina]

The flaw is two-fold? If I'm understanding this correctly Fadden is using a flawed premise (the lack of evidence as evidence of falsity) to make a flawed argument (that his argument cannot be undermined without being destroyed).

Fadden: You have no way of showing that customers were lying (flaw one). Your objection is absurd (flaw two).

That seems complicated.

It does. TBH I don't think I would have gotten this question right without ample time to think about it, but that's my interpretation. The good news is, while the correct answer choice may not be the most obvious, the incorrect answer choices will all be 100% wrong, so this might be a good question where process of elimination is your strategy of choice.

[ahri]

i totally agree with you cc celina. but i'm just thrown off by how like you said "He's not attacking the truth of Greenwall's assertion from any reasonable grounds, and he dismisses Greenwall's objection as "absurd" because it does not have concrete evidence to back it up" isn't one of the answer choices, even though it's the clearest flaw.
(i know sometimes some flaw questions have more than one flaw but they only list one of them but i feel like it's always the most blatant one that's always listed)
The best way i can describe my problem with this question is if you only take the first two parts of the dialogue. you could never conclude faden believes he has the unwarranted assumption (the one i'm having trouble with), but if you take the last two parts of the dialogue like this:

Greenwall: but many of those customers could easily be lying because they are too embarrassed to admit that they don't exercise anymore.

Faden: you have no way of showing that customers were lying. your objections is absurd.

The flaw most obvious is he dismisses greenwall's argument based on the unwarranted assumption of no evidence means it's false.

when i add all 3 statements together, i don't see how faden's last statement puts conditions on what constitutes as necessary to weakening his argument. "you have no way of showing that customers were lying" attacks greenwall's statement, and he concludes "your objections is absurd. "

While the answer choice makes it seem like he assumed to qualify which type of statements can weaken his view.

the conditional statement: Evidence for a claim has been undermined->that evidence has been proven false

That means other evidences that don't prove his evidence false (even though there are tons of weakeners that don't prove the other persons facts are wrong such as it's unrepresentative data) could never undermined his conclusion.

It's as though this answer should have been for a question like this:

Jake: sally wouldn't like those earrings because she typically doesn't like black
Tom: however, they are really nice and i heard she liked them.
Jake: well since you didn't say she likes black, sally wouldn't like those earrings.

[cc.celina]

That means other evidences that don't prove his evidence false (even though there are tons of weakeners that don't prove the other persons facts are wrong such as it's unrepresentative data) could never undermined his conclusion.

Exactly, that's why it's a flaw. Fadden argues that NO weakener could POSSIBLY weaken his conclusion unless it PROVES that his evidence, the consumer survey, is false. (We know this is wrong - Greenwall's point clearly weakens Fadden's conclusion.)

While the answer choice makes it seem like he assumed to qualify which type of statements can weaken his view.

The answer choice did indeed make it seem that way, because it is that way. You're right that Fadden may not have explicitly stated, "Only if you disprove my evidence will you weaken my conclusion."

However, his statement is essentially a mini-argument, consisting of 1 premise (in addition to those already presented) and 1 conclusion. Think of his statement this way: "Because you have no way of showing that customers are lying, your objection is absurd." Now it DOES seem like he's qualifying which statements are absurd and which aren't - the ones that Greenwall can't prove are the absurd ones.


Tip - flaw questions are by no means always the most obvious to you. For one thing, that would make them all too easy, and for another, not everyone will think the same flaw is obvious. In many instances, for example, I have seen shifts in language that I thought undermined the conclusion, but they didn't show up anywhere in the answer choices.

[ahri]

The flaw is two-fold? If I'm understanding this correctly Fadden is using a flawed premise (the lack of evidence as evidence of falsity) to make a flawed argument (that his argument cannot be undermined without being destroyed).

Fadden: You have no way of showing that customers were lying (flaw one). Your objection is absurd (flaw two).

That seems complicated.

D holy crap... now i understand it a lot better. Thanks guys. my book is a kaplan by the way and it doesn't even come close to your explanation.

it told me to recognize the no evidence doesn't mean false evidence rule for this question which i understood but it didn't point out the 2nd flaw which is the actual important part. You guys are awesome and sorry for taking so long to finally get it but cc celina you broke it down perfectly.

[cc.celina]

No problem! Glad our teamwork could help you out

[Clearly]

Great discussion. If (while your breaking the rules) you wouldn't mind posting the other answer choices, I'd be curious to see them. This wording wouldn't have been my prephrased answer, but I suspect none of the other answer choices would be particularly tempting (Or this is a genuinely tricky flaw question) That said, Old tests are usually pretty strange to me. I do very well on LR, but tend to fly from experience, and the wording of this answer choice doesn't tempt me right away. It comes off like one of those "wtf jargon" wrong answer choices I love seeing: "The argument relies critically on assuming an assumption which is assumed to be presumed"

[Clearly]

Also, CC, you rock.

[03152016]

.

[polobull]

No problem! Glad our teamwork could help you out

You and I could write a test prep book: you do all the complicated analysis and explaining and I, in the role of Bill Gates' quintessential lazy person, will follow up and interpret your work with brutal clarity. You'll get the credit, deservedly, and we'll both get rich