#9 - During the three months before and the three months

[powerguy]

Why is E) incorrect?

Premise says A group of college students who had never experienced an earthquake recorded their dreams' + 'Almost none of the students in Ontario reported dreaming about earthquakes' -- means there were 1-2 people who had dreams of earthquake had so after the earthquake. Doesn't it strengthen?

Secondly, what does "almost none" mean? 1 person?

Thanks

[Nikki Siclunov]

(E) is a much weaker way of strengthening the argument than (A) is. The fact remains that almost none of the students in Ontario reported dreaming about earthquakes after the CA earthquake, compared to half of those in CA. Just because a few Ontario students reported such dreams after the earthquake means very little: we don't know what the typical frequency of earthquake-related dreams is in general. Maybe earthquakes occur in 1-2% of all dreams regardless of whether we experience earthquakes or not.

Now, consider (A): the big problem with the study is that they never tell us what the Cali students dreamed of before the earthquake. If most of them tend to dream about earthquakes anyway, then the argument would be a lot weaker. But if fewer Cali students than Ontario students dreamed of earthquakes before the recent earthquake, that would suggest that almost none of the Cali students dreamed of earthquakes before. This would make the correlation much stronger, supporting the causal conclusion based upon it.

Let me know if this helps!

[powerguy]

Thanks Nikki. It's clear now. Just a couple of questions, on the lsat,

question #1 : almost none ~ 1-2 people. IS that correct? I have heard my friends saying that it means "none"

question#2: do you think that the below table is okay?

(source: http://www.sejarchive.org/resource/IPCC_terminology.htm)
Likelihood of an outcome or result

"Virtually certain" means greater than a 99 percent probability of occurrence.
"Extremely likely" means greater than 95 percent.
"Very likely" means greater than 90 percent.
"Likely" means greater than 66 percent.
"More likely than not" means greater than 50 percent.
"About as likely as not" means 33 to 66 percent.
"Unlikely" means less than 33 percent.
"Very unlikely" means less than 10 percent.
"Extremely unlikely" means less than 5 percent.
"Exceptionally unlikely" means less than 1 percent.
Relative degrees of confidence in a statement

"Very high confidence" means at least a 9 out of 10 chance of being correct.
"High confidence" means about an 8 out of 10 chance.
"Medium confidence" means about a 5 out of 10 chance.
"Low confidence" means about a 2 out of 10 chance.
"Very low confidence" means less than a 1 out of 10 chance.

[Jon Denning]

The LSAT doesn't require you to quantify language with that type of specificity. All you really need to know:

All, every, none, half etc are absolute and easy to define

Most = majority, so more than half

Some = at least one, so anywhere from 1 to all

Not all = anywhere from 0 to all-minus-one (0-99 on a scale of 0-100)

All the other stuff you reference can be thought of in terms of where it would fall in the broader categories above. Pretty straightforward

[lsatnoobie]

I chose A because it’s a much better AC than C, but other than intuition, I’m having a hard time explaining to myself why c is wrong. Could you help?

[James Finch]

Hi LSATNoobie,

The conclusion here is trying to draw a causal link between experiencing at least one earthquake and dreaming about earthquakes. Two studies are provided for support. The control study (Ontario) shows that people who have not experienced an earthquake rarely dream about them. The experimental study (California) shows that after having experienced an earthquake, half of the participants dreamed about earthquakes. The problem is that we aren't given the baseline for the experimental study participants; maybe the half of them that dreamed about earthquakes after experiencing one already dreamed about earthquakes before experiencing one.

Answer choice (A) directly addresses this issue by telling us that the rate had been the same as in the control (Ontario) study, giving a major boost to the likelihood that the conclusion is correct.

Answer choice (C), meanwhile, does nothing to the argument in the stimulus because it fails to tie the cause of experiencing an earthquake to dreaming about them. "Many" is a vague term that could encompass all or none of the 50% who dreamed about earthquakes after experiencing the one in California, so it fails to strengthen or even weaken any link between the experience of an earthquake and dreaming about.

Hope this clears things up!

[PresidentLSAT]

Hello Powerscore,

48th President of the United States here. Ok so here's my question. I'm afraid I eliminated E for a different reason. Who really cares about the dreams of the Ontario students? The conclusion here is about STUDENTS WHO EXPEREINCE earthquakes-and they didn't, I don't see how any information about the Canadian students could strengthen our argument.

I tried comparing with A- "ok they probably just watched a blockbusters box office international hit- that is why both groups in A and E are dreaming about earthquakes. But here is where I love this torture of a process called LSAT. A, by directly establishing that right before the earthquake 5 out of 500 students from each group had dreams about earthquakes. (They probably watched something on the news). A is stronger because if 250 out of that 500 in CA are suddenly dreaming about earthquakes after it hit their backyard, and the number was 5 out of 500 (same as their Canadian counterparts) before the earthquake hit, the argument is strengthen by using the data to back the claim that their personal experience led to their dreams.

Am I on the right path? This question is important to my future Presidency lol

[Adam Tyson]

Your election prospects are looking good, 48! What you have described in your analysis, whether you realize it or not, is "where the cause is absent, the effect is also absent," which is a classic way to strengthen a causal argument. If the claim is that experiencing an earthquake causes one to dream about earthquakes, then it would sure help if the people who had not yet experienced one weren't already dreaming about one!

To me, answer E looks like it weakens a little. It's not experiencing an earthquake that causes those dreams, but maybe just hearing about one on the news that is the cause? It's a lame weakener because of the numbers, and also because the causal language is soft (can cause rather than does cause), but it's still a slight negative and not at all helpful to the argument.

Good work, you get my vote!

[LSAT student]

When reading the last sentence of the stimulus, and then reading answer (E), I don't see how it doesn't help the argument? What about answer E makes it incorrect? If (A) were not an option, would (E) then be correct?

[Robert Carroll]

LSAT student,

There is no possible way that two answers could correctly answer an LSAT question, so if answer choice (A) were not present among the choices, nothing would work. Answer choice (E) simply does not help the argument at all. None of the Ontario students ever experienced an earthquake. If a few of them started having dreams after the California earthquake, which none of the Ontario students experienced, then we'd have at least a few cases of dreams about earthquakes among people who never experienced an earthquake. Among those people, at least, their dreams were not caused by earthquakes, so those Ontario students are counterexamples to the conclusion. That certainly is not good for the argument.

Robert Carroll