#19- The coach of the Eagles used a computer analysis to

[rachue]

Hi, I"m having trouble understanding why A is incorrect.

This is how I diagrammed the stimulus:

P: no Jen ---> lose
C: Jen ---> don't lose

So isn't the flaw in the argument a MR, and therefore A?

[Dave Killoran]

The diagram in the first sentence is actually reverse of what you have. The "only when" operates just like "only if," and so the diagram in the first sentence is actually:

Lost --> no Jen

That means that it isn't a Mistaken Reversal in the conclusion (or an MN), and we need to look elsewhere for the error.

Think about this for a second. Thus far, when the Eagles lose, Jen doesn't play. Based on that, the author concludes that if we put Jen in the game, it is confirmed that the Eagles will win. Is that really confirmed? If not, what's the mistake there? Thinking that what happened in the past will always happen again in the future. That's what answer choice (D) is driving at, and thus (D) is correct.

For the record, this is a tough question (#19 questions are often very difficult), and (A) is perfectly placed to catch anyone who sees the conditionality and mis-diagrams it. Make sure you know those conditional indicators!

One last thing: the two diagrams you have are actually Mistaken Negations of each other, not MRs, just to be picky

Let me know if that helps. Thanks!

[rachue]

That does help! I guess I need to work more on strengthening my understanding of S/N. Thanks again!

[netherlands]

Hi there PS,

I wasn't sure, is "only when" a conditional indicator?

[David Boyle]

Hi there PS,

I wasn't sure, is "only when" a conditional indicator?

Hello,

"Only when" is pretty much synonymous with "only if".

David

[Applesaid]

hello!

Again this is my headache of flaw in the reasoning question. Since I cannot see what's wrong with the stimulus, I could barely pick up an answer choice even via the power of elimination. I will be very grateful if anyone can help me with this! Thanks


Celine

[KelseyWoods]

Hi Celine!

The flaw with this stimulus is that the author is assuming that just because Jennifer was in all the games they won in the past, that her playing in future games will ensure that they win. That's a temporal flaw which matches what answer choice (D) describes.

Answer choice (A) describes a conditional flaw but we don't have a conditional flaw here.

Answer choice (B) says that the author assumes that you can use a computer to quantify a player's contribution to a team. The argument does assume that this is possible (though it also states that it's not necessary) but it is not the flaw in the argument. It could be possible to use a computer to determine that Jennifer was enough to ensure that the Eagles won their past games, but that doesn't mean we can reliably make any conclusions about their future games.

Answer choice (C) describes an overgeneralization but the premises and the conclusion are both about this one specific player and this one specific team. The conclusion does not concern the applications of computer analyses to sports as a whole.

Answer choice (E) technically describes something that occurs in the stimulus but it doesn't describe a flaw.

Hope that helps!

Best,
Kelsey

[Annah]

Hi Kelsey!

Could you please elaborate on how there is no conditional reasoning involved in this question and why answer choice A is incorrect?
I initially assumed that the use of "only when" might be used to construct a conditional statement but then moved on to the conclusion and read 'Jennifer's presence in the game will ensure that the Eagles will win' as 'The presence of Jennifer is sufficient for the team to win'.
If Jennifer's presence Eagles win
then the contrapositive would be the Eagles don't win Jennifer not present
which is the equivalent of the team losing if Jennifer does not play.
Answer Choice A states 'the absence of the sufficient factor is necessary (Jennifer not present as the NC in the contrapositive) for the opposite result' (Eagles do not win as the SC in the contrapositive).
Therefore, by way of the contrapositive is Answer Choice A not the correct flaw?

[Nikki Siclunov]

Hi Annah,

You're absolutely correct in that there are elements of conditional reasoning here. However, the flaw has nothing to do with them. Let me explain:

The only premise for the author's conclusion is the analysis revealing that the team has lost (i.e. not won) only when Jennifer was not playing:

Premise: NOT win NO Jennifer

By the contrapositive, we can conclude that whenever Jennifer played, the team won:

Contrapositive/Conclusion: Jennifer Win

The contrapositive is consistent with the conclusion of the argument, and - since the contrapositive is a logically valid way of drawing an inferential conclusion - the argument is not flawed from a conditional reasoning standpoint. However, as Kelsey explained, the flaw is temporal: although the team may have won every time Jennifer was playing, we cannot extrapolate a similar outcome in the future. This is precisely what the author did, arguing that Jennifer's presence will ensure that the Eagles will win. This is why answer choice (D) is correct.

Notice that answer choice (A) describes precisely the operative function of a contrapositive: indeed, if a certain factor (A) is sufficient for a result (B), the absence of that factor (NOT A) is necessary for the opposite result (NOT B):

Premise: A B
Conclusion: NOT B NOT A

As discussed earlier, this is not a logical flaw, making answer choice (A) incorrect.

Let me know if this clears things up

[Nikki Siclunov]

One last point about that: not every Flaw question with conditional reasoning in the stimulus will have a conditional reasoning flaw. Although this happens more often than not, and was particularly common in the past, the argument can be flawed for a variety of other reasons having nothing to do with the elements of conditional reasoning in it.