Q6 - Videocassette recorders (VCRs)

[yimei]

Videocassette recorders (VCRs) enable people to watch movies at home on videotape. People who own VCRs go to movie theaters more often than do people who do not own VCRs. Contrary to popular belief, therefore, owning a VCR actually stimulates people to go to movie theaters more often than they otherwise would.

The argument is most vulnerable to criticism on the grounds that it

(A) concludes that a claim must be false because of the mere absence of evidence in its favor

(B) cites in support of the conclusion evidence that is inconsistent with other information that is provided

(C) fails to establish that the phenomena interpreted as cause and effect are not both direct effects of some other factor

(D) takes a condition that by itself guarantees the occurrence of a certain phenomenon to be a condition that therefore must be met for that phenomenon to occur

(E) bases a broad claim about the behavior of people in general on a comparison between two groups of people that together include only a small proportion of people overall

Can someone explain Option D ?

[maryadkins]

No need to reprint the question, we got it!

This is a flaw question, so we want to start first by finding the core.

The core here is:

VHS owners go to the movies more --> having a VHS stimulates people to go to more movies

Immediately my CAUSATION VERSUS CORRELATION buzzer is making crazy loud noises. Just because two things are correlated or associated (in this case, owning a VHS and going to more movies) doesn't mean one causes the other. Maybe going to a lot of movies means you love movies, and so you're more likely to buy a VHS (if it were 1982). Maybe people who are in the film industry just go to more movies and buy VHS players--that would be a third cause driving both VHS ownership and movie-going.

(C) says this.

(D) is a convoluted but somewhat common way the LSAT describes logic reversal on the LSAT. It's saying the argument mistakes a sufficient condition for a necessary one. It's describing a situation in which you'd been told as a premise, "If you're in Canada, you're in North America," and the argument then concluded, "If you're in North America, you're in Canada." Not what the argument is doing, here.

(B) describes conflicting information which we don't have.

(A) is wrong because there isn't a claim of missing evidence.

(E) makes it about sample size. As soon as you see the correlation-causation problem, which should jump out at you by the time you've done enough of these, (E) won't be tempting.

[VendelaG465]

How can I differentiate next time the diff. between Sampling & Cause vs. Corr.? I mix the two up often.

[VendelaG465]

I had picked E originally *

[ohthatpatrick]

They don't really have anything in common that I can think of, so you should probably re-read the part of the Flaw chapter describing them, and you should try to write your own examples of each flaw and email them to your teacher to check them for accuracy.

Correlation vs. Causality
needs a correlation in the evidence
and a causal claim in the conclusion

What do correlations sound like?
(If you can't answer this on your own, this is very important to flashcard and memorize)

What do causal claims sound like?
(If you can't answer this on your own, this is very important to flashcard and memorize)

CORRELATIONS
Most X's are Y
X is associated with Y
X is correlated with Y
people who are X tend to be Y
people who are X are more likely to be Y than those who aren't (most common)

In this argument, we had a correlation premise that said
"Ppl who own VCRs go to movies more often than do ppl who don't own VCRs"

CAUSAL CLAIMS (it's all about the verb)
X causes Y
X leads to Y
X promotes Y
X influences Y
X contributes to Y
X is responsible for Y

In this argument, we had a causal conclusion that said
"Owning a VCR actually stimulates people to go to the movies"

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

SAMPLING
This is when you have a premise about a small group of people, and then the conclusion makes the SAME claim about a bigger group of people.

ex:
The three people I asked thought that the new "Star Wars" was great.
Thus, Star Wars fans everywhere must be happy with the new installment.