#23 - Linda says that, as a scientist, she knows that no

[eober]

Hi,

I was wondering if this question is an example to mistaken negation?

Thanks!

[David Boyle]

Hi,

I was wondering if this question is an example to mistaken negation?

Thanks!

Hello eober,

One may diagram:

S (scientist) ----> slash AP (appreciate poetry);


S

most
----> L (logical);

AP

some
----> slash L.


Answer B replicates this by saying,

F ----> slash WCEC (want children eat candy);


F

most
----> A (adults);


WCEC

some
----> slash A (since adults are not children, and vice versa).

Same logical-flaw structure in each argument. But I think it is a little too complicated, among other things, to call a "mistaken negation"; a Mistaken Negation would be something like, "If you are not a scientist, you do appreciate poetry." But that does not really appear among what we diagrammed above.

Hope this helps,
David

[kristinaroz93]

Linda says that, as a scientist, she knows that no scientist appreciates poetry....

Please let me know if my reasoning for this problem is correct:
Stimulus:
Logical<--(most)-- Scientists <--/--> appreciate poetry
conclusion: appreciate poetry <---(some)---> not logical

However, the conclusion should actually be: logical<---(some)--> not appreciate poetry
(I am not sure how to describe this error but it looks like a form of mistaken negation (and not mistaken reversal since elements can be reversed when we are talking about "some"). What would be the correct way to describe the error if I am wrong?)

And so then B is correct since it has this similar kind of mistaken negation error:
adults <----(most)---Father <---/---> want children to eat candy at bed time
conclusion: not adults <---(some)---> want children to eat candy at bed time
(children= not adults)
when the conclusions should be: adults <---(some)---> not want children to eat candy at bed time

A) Valid (we can safely assume marsupials are animals right?)
native to austrailia<--(most)---marsupial<---/-----> lay eggs
conlusion: animals nativa to austrailia <---(some)---> not lay eggs
E) not valid
honest people <---(most)---- corporate executive <---/---> like to pay taxes
conclusion: honest people <---(some)---> like to pay taxes
conclusions should be:
honest people <---(some)---> not like to pay taxes
(This is different from the stimulus, since the stimulus puts a "not" in the conclusion on the wrong term, whereas there is no "not" term placed whatsoever in the incorrect conclusion of e!)

C) There is no "some" term in the conclusion to parallel the conclusion of the stimulus.

D) invalid reasoning
instant film ---(most)-->color film<---/---> produce imgaes as sharp as best black and white film
conclusion: instant film <---(some)----> not produce imgages as sharp as best black and white film
(The most arrow for most is going in the wrong direction which means no conslusion can be made, and because the arrow for most is going the wrong way it is also in this regard different from the stimuulus.

Please let me know about my reasoning thus far and how to do a problem of this nature quicky on a test !

[Steve Stein]

Hey Kristin,

That's an interesting question. Linda begins by saying that as a scientist she knows that no scientist appreciates poetry. In other words, if you are a scientist, you do not appreciate poetry, and she goes on to say that most scientists are logical:

• scientist appreciate poetry
  
  scientists logical

It's imporant to note at this point that "most" means more than half, which includes the possibility of "all." So, it's possible that all scientists are logical. If that is the case, then we know something about logical people (namely, that some logical people are scientists who appreciate poetry), but we can glean nothing at all about illogical people.


Answer choice (B) parallels this flawed reasoning: It provides that Franz ,as a father, knows that no father wants children to eat candy at bedtime. In other words, if you are a father, you do not want children to eat candy at bedtime. He goes on to say that most fathers are adults:

father want children to eat candy at bedtime

fathers adults

Again, we should note that "most" includes the possibility of "all," and in this case seems to refer to exactly that (since common sense tells us that all fathers are adults, physiologically speaking). If that is the case, then we know something about adults (namely, that some adults are fathers who do not want children eating candy at bedtime), but we can glean nothing at all about non-adults.


Tricky question! I hope this is helpful—please let me know whether this is clear—thanks!

~Steve

[kristinaroz93]

H Steve,

Thanks for responding.

I think you meant to say here, " (namely, that some logical people are scientists who [do not] appreciate poetry)", right?

I get what you are saying, but was every aspect of my own reasoning fully wrong then?

And Could you go through the other answer choices as well please=)

[Steve Stein]

Hey Kristen,

Thanks for your response. Your diagram about logical, non-poetry-appreciating scientists is valid! And your analysis of answer choice (A) is correct, presuming that there are marsupials in existence today. You’re analysis looks good with regard to answer choice (C) and answer choice (E), though the reasoning in answer choice (D) is valid:

Instant-- most  color film  less sharp than best b&w
Thus, we can conclude that most instant film is less sharp than the best black and white. If that is the case, then surely some instant film is less sharp than the best black and white.

Some of these can be pretty challenging, and it seems like you’ve got a pretty solid grasp on the concepts. I think the best way to improve your timing is to practice. It’s also valuable to note that this sort of question can be very time consuming, so when you encounter a question that looks like this one, it might be a good one to skip, and then come back to, time-allowing.

I hope that's helpful! Please let me know if anything is unclear—thanks!

~Steve

[kristinaroz93]

Hi Steve,

I see where I went wrong with my explanation of choice D earlier: "D) invalid reasoning
instant film ---(most)-->color film<---/---> produce imgaes as sharp as best black and white film
conclusion: instant film <---(some)----> not produce imgages as sharp as best black and white film
The most arrow for most is going in the wrong direction which means no conclusion can be made, and because the arrow for most is going the wrong way it is also in this regard different from the stimuulus."

Question 1 )**The arrow is going in the right direction and also most contains some, so it is valid to conclude that some instant film does not produce images as sharp as the best black and white film. However had the most sign gone the opposite way (i.e. instant film<---(most)--color film<---/---> produce imgaes as sharp as best black and white film, we would still reach the same valid conclusion of "instant film <---(some)----> not produce imgages as sharp as best black and white film", correct?)

Question 2) And also a better explanation of why E is wrong, is because it didn't switch out honest people for dishonest people. In other words the conclusion didn't bring in a comepletely different set of people never mentioned before in the stimulus. It kept talking about honest people all the way through, even though the conclusion was still wrong. I think this is better than what I said earlier, please let me know what you think=) ! )


I await your response and thanks in advance for helping =)

[Steve Stein]

Hey Kristin,

Looks like you've got it! Nice work!

~Steve

[kristinaroz93]

Hi Steve,

I kept editing the question to make it as clear as possible, are both my questions 1 and 2 fully correct (even for 1 where switiching out the arrow for most is irreleveant as we get to the same conclusion in that one case=)?

(I ask becasue I don;t know what version of my post you read, I added in question 2 last minute before your response came in I think =p

[Steve Stein]

Hey Kristen,

Thanks for the follow-up message—you were correct, I had responded to the first question before you posted the second one. Answer choice (E) looks good right up until the end. If the conclusion had instead been that at least some people who like to pay taxes are dishonest, that would have created a valid parallel with the stimulus. I believe that is the point you made in your more recent post.

I hope that's helpful—please let me know whether this answers your question—thanks!

~Steve