PT71.S3.Q18 - videoconferencing equipment

Quick Silver

http://7sage.com/lsat_explanations/lsat-71-section-3-question-18/

I thought the answer might be D for a very different reason.... the circumstances are specifically described as being about people who don't already own the item, but the survey is about people who do own the item. ie... if you don't already own a GPS system in your car, don't buy one because most cell phones have them - and of course most people who already own a GPS system in their car will like it.... but, again, it's not worth buying because you likely already have a cell phone with GPS.....In sum, I can see that being the reasoning behind D, with the sample being the survey as a whole --- and the group actually referring to people that don't own these things already.

But I have difficulty seeing the explanation JY gave... we're often given survey results - and in surveys there usually is a discrepancy between people who respond and people who don't.... why are we splitting hairs over it here? ie 55 percent of respondents prefer candidate X.... In an LSAT question we normally wouldn't dismiss the result simply because MAYBE there's a discrepancy between respondents and non-respondents... I think LSAC would give us a differently worded question or maybe we'd have to guess the Nec. Assum. But respondent deviation seems way too subtle - even for LSAC - to be the reasoning behind choice D.

Thoughts?

[Deleted User]

you're using real world logic

when you take the lsat you have to stay within bounds of the lsat and the stimulus

you should not use real world logic because then a lot of answers that are wrong will suddently become attractive, or you may hesitate with an answerchoice that is correct.

David Wayne

Hey Quick Silver,

Your analysis is correct and your allegedly inappropriate 'real world logic' is actually quite LSAT-esque and pertinent to this problem (i completely disagree with the above comment, and you should too. No offense intended though, just speaking for the sake of our LSAT knowledge). JY actually alludes to your reasoning while pointing out something else you may not have noticed. At minute 2:00, he says that the sample is likely to be unrepresentative because the respondents are from a group of people who already own it, and ON TOP OF THAT (he says this) they are unlikely to be representative (alluding to the respondent discrepancy you pointed out). However, while alluding to your absolutely valid explanation of the answer choice, JY seems to prefer the respondent/non respondent discrepancy as the main thrust of his video's explanation.

It is definitely the case that this argument fails to account for the possibility of sample bias; namely, that these businesses were already in a position that made these systems better for their particular businesses. To use your scenario, perhaps the GPS owners like them because people who love GPS's refuse to purchase cell phones. There are a host of reasons why the group of video conference system owners are unlikely to be representative of businesses in general.

I actually agree that it may not be the case that the LSAT was intending readers to identify the respondent/non-respondent discrepancy. I've never seen a flaw question using samples that are flawed because of the respondent/non-respondent discrepancy, but i actually think it may be something we're supposed to keep in mind.

If you take a look at the June 2007 LSAT, look at question 15 of the 2nd LR section. One of the answer choices (that actually turns out to be incorrect) raises the possibility of a respondent/non-respondent discrepancy possibly weakening the argument. From that answer choice, it does seem like the LSAT writers may indeed be thinking about this. It seems like the LSAT defines a survey as something that participating in is optional, so it would be wise to actually keep this in mind. Maybe that's a bit of a stretch. What do you think?

Quick Silver

Thanks so much CJW (and Ttunden) - Very Helpful!