Q9 - Two lakes in the Pawpaw mountains

[TimaK]

I originally chose A because I thought that A showed that the author failed to consider other possibilities. So if Highwater Lake has acid rain, then that would explain why the fish population continues to decline. But after seeing the answer, I realized that A doesn't undermine the conclusion because it has nothing to do with Quapaw Lake. Is that correct?

[db_8400]

I believe A is not correct because we dont know if Acid Rain actually kills the fish. It could do a number of possible things besides kill them maybe the acid rain can give them some type of disease and still live or make them breed more who knows! So I didn't pick A bc of that. Answer choice A is the most tempting out of the incorrect answers though.



Also as a side note I believe LSAC put this answer choice first because people commonly assume Acid Rain is dangerous and can cause sometype of harm and you automatically think it will harm/kill the fish. This is a pretty common technique they use!

[ohthatpatrick]

You clearly picked up on the causality in the conclusion and started anticipating alternative causes as the correct answer to a Weaken question.

Great work!

Even though that is the dominant tendency for Weaken questions, remember that for ANY causal explanation conclusion, there are actually TWO possible pressure points:

1. Plausibility of the Author's explanation
2. Possibility of Alternative explanations

Let me put up a complete explanation of Q9

=================

Question Type: Weaken

ARGUMENT CORE
conclusion
Ban on fishing probably caused the uptick in fish population at Q Lake

evidence
10 yrs. ago, Q Lake and H Lake were both seeing declining fish population
+
Ban on fishing at Q Lake started, and fish population is back to normal
+
No ban on fishing at H Lake, and fish population still declining

ANALYSIS
There are two pressure points the correct answer could attack:

1. Is it plausible that the ban on fishing at Q Lake could have helped restore the fishing population? (maybe fishermen typically ignore bans and continue fishing anyway)

2. Could something else have caused Q Lake's fish population to come back to normal?

ANSWER CHOICES

(A) Irrelevant --- What does this have to do with Q Lake?

One could argue that this somewhat weakens by lessening the effectiveness of the author's last premise. She attempted to bolster the idea that THE BAN caused the FISH RECOVERY by showing "no cause, no effect" at H Lake -- No Ban, No Fish recovery.

(A) seems to provide an alternate cause for No Fish Recovery at H Lake.

One big problem is that the language of (A) in no way distinguishes H Lake from Q Lake, in terms of acid rain.

Had it said "particularly susceptible" or "more susceptible than Q Lake", it would have more effect. It's possible that Q Lake is also highly susceptible to acid rain (maybe even likely -- they are two lakes in the same mountain range).

(B) This answer looks good. It's in the style of Pressure Point #1. How could a ban on fishing have caused the Fish Recovery at Q Lake if fishing was never a problem there in the first place?

It's like saying, Billy's GPA was mediocre, but since he got that Math tutor, his GPA improved. The Math tutor must be responsible.

It would weaken that argument to say, "Billy was getting an A in Math prior to being tutored."

(C) Irrelevant --- "Larger" is not an interesting distinction.

(D) This gently alludes to the possibility of an alternative cause for the rebounding population at Q Lake ... or does it? Maybe these other lakes ALSO had fishing bans! This doesn't give us enough of a hypothesis to go off of. Had this been worded, "Several other lakes in Pawpaw that did not have a fishing ban have also had increases in their fish populations over the past ten years", then it weakens.

(E) Irrelevant --- "variety" of fish is not an interesting distinction.

The correct answer is (B).

Let us know if you have follow-up questions.

[huskybins]

But for B to be correct, we must also assume there was no more fishing after the ban on Q lake than that prior to the ban, mustn't we? Otherwise, that could mean there were more fishing after the ban whereas we still see an increase in fish population, which may hint a corroboration on the original point made in the stimulus, i.e. the fishing ban contributes to the increase of fish population in Q lake.

I don't say B is not the correct answer especially comparing to the other 4, but still it seems necessary to have the stretch above in order to make it a valid weakening option.

You clearly picked up on the causality in the conclusion and started anticipating alternative causes as the correct answer to a Weaken question.

Great work!

Even though that is the dominant tendency for Weaken questions, remember that for ANY causal explanation conclusion, there are actually TWO possible pressure points:

1. Plausibility of the Author's explanation
2. Possibility of Alternative explanations

Let me put up a complete explanation of Q9

=================

Question Type: Weaken

ARGUMENT CORE
conclusion
Ban on fishing probably caused the uptick in fish population at Q Lake

evidence
10 yrs. ago, Q Lake and H Lake were both seeing declining fish population
+
Ban on fishing at Q Lake started, and fish population is back to normal
+
No ban on fishing at H Lake, and fish population still declining

ANALYSIS
There are two pressure points the correct answer could attack:

1. Is it plausible that the ban on fishing at Q Lake could have helped restore the fishing population? (maybe fishermen typically ignore bans and continue fishing anyway)

2. Could something else have caused Q Lake's fish population to come back to normal?

ANSWER CHOICES

(A) Irrelevant --- What does this have to do with Q Lake?

One could argue that this somewhat weakens by lessening the effectiveness of the author's last premise. She attempted to bolster the idea that THE BAN caused the FISH RECOVERY by showing "no cause, no effect" at H Lake -- No Ban, No Fish recovery.

(A) seems to provide an alternate cause for No Fish Recovery at H Lake.

One big problem is that the language of (A) in no way distinguishes H Lake from Q Lake, in terms of acid rain.

Had it said "particularly susceptible" or "more susceptible than Q Lake", it would have more effect. It's possible that Q Lake is also highly susceptible to acid rain (maybe even likely -- they are two lakes in the same mountain range).

(B) This answer looks good. It's in the style of Pressure Point #1. How could a ban on fishing have caused the Fish Recovery at Q Lake if fishing was never a problem there in the first place?

It's like saying, Billy's GPA was mediocre, but since he got that Math tutor, his GPA improved. The Math tutor must be responsible.

It would weaken that argument to say, "Billy was getting an A in Math prior to being tutored."

(C) Irrelevant --- "Larger" is not an interesting distinction.

(D) This gently alludes to the possibility of an alternative cause for the rebounding population at Q Lake ... or does it? Maybe these other lakes ALSO had fishing bans! This doesn't give us enough of a hypothesis to go off of. Had this been worded, "Several other lakes in Pawpaw that did not have a fishing ban have also had increases in their fish populations over the past ten years", then it weakens.

(E) Irrelevant --- "variety" of fish is not an interesting distinction.

The correct answer is (B).

Let us know if you have follow-up questions.

[ohthatpatrick]

The correct answer to Strengthen or Weaken will never prove or refute.

So, SURE! You could still make the author win the argument.

But we successfully "scored a point", which is all we're trying to do on Strengthen / Weaken.

If you picture the Conclusion and Anti-Conclusion as opposite goalposts (or endzones, if you know American football), just think of Strengthen/Weaken as nudging the argument in one direction or the other.

Only Sufficient Assumption is meant to take us all the way into an endzone.

If we said:
"Who ate the last peanut butter cookie? Since Reggie just passed through the kitchen a few minutes ago, it must have been him!"

Am I weakening that argument if I say:
"Reggie hates peanut butter cookies and has an allergy to peanuts."

Of course!

Is it still possible that Reggie ate the cookie? Of course.

Hope that makes sense.

[JohnZ880]

Here's another potential explanation for why (B) is correct, although I'm not sure if I'm hitting the mark here or not. (B), in more abstract terms, is taking away the correlation that was implied in the argument and therefore casting tons of doubt on the causal conclusion. Put another way, this question tests the opposite of the famous phrase, "correlation doesn't imply causation." Causation, on the other hand, almost always implies correlation.

The argument is that fishing is correlated with the decline in the fish population. If there's no more correlation, then we can't draw a causal inference.