Q2 - For a television program about astrology ...

[soyeonjeon]

I chose D for this one. Could someone help me understand this type of problem?
Thank you.

[tommywallach]

Hey Soyeon,

This is an "identify the flaw" question. We start by isolating the core: conclusion and premise.

Conclusion: Your signs influences your personality.
Premise: Twenty volunteers on the street were Geminis and more sociable/extroverted than average

This argument is assuming that there isn't some other reason the people chosen were more sociable/extroverted than average. The correct answer will identify this assumption and reword it as a flaw.

(A) We don't care who scored/administered it, as long as the results are valid.

(B) This is about the judgment of astrologers, which is irrelevant here. We're doing science!

(C) This would prove that the investigators are good judges of character, not that astrology had anything to do with character.

(D) This is irrelevant. The investigators purposely found 20 geminis. It doesn't matter how many of them there were out on the street. If astrology affects personality, they could be the ONLY 20 geminis on the street.

(E) CORRECT. This provides another reason why the sample of people might have been more gregarious than average.

Hope that helps!

-t

[WaltGrace1983]

To reiterate, it doesn't matter WHERE they got the participants (unless maybe they got all the participants at the "Convention of Extremely Social and Extroverted People"). All that matters here is that they got them. I could interview 20 Geminis on the street, in a store, in my own home, it wouldn't matter as long as these Geminis were representative of all the Geminis. If we only chose a certain type of Gemini then how could they be representative of the whole Gemini population? In this case we did choose only a certain type of Gemini - one's that wanted to take a poll. However, what if the ones that wanted to take the poll are the only extroverted Geminis are everyone who turned down the poll were introverted Geminis? This would skew the results, as the answer choice exposes here.

[ZLG870]

My intuition guides me to choose E, but I am really confused about the Gemini stuff.
After thorough consideration, something comes into mind that I wanna share with you guys. I think the claim mistakes the incorrect cause for the correct one. Volunteers under the sign of Gemini were willing to take a test. These volunteers are sociable and extroverted, according to the investigator. Then we get the conclusion that one's astrological sign influences one's personality. ( in other words, people born under the sign of Gemini are extroverted and sociable. ) But actually the real causal relationship is that people who are willing to take a test are more extroverted and sociable. This is the true reason. That is exactly what E says.

A person with characteristics with A and B tends to do C. We may not assume A is the reason for the action C. Maybe B plays a role in such relationship.
I find the causal relationship is useful for analyzing a lot of assumption family questions. Hope this helps