#13 - A recent study of 10,000 people who were involved in

[Dianapoo]

Hello all. I want to make sure I'm thinking about this problem correctly.

The first thing I noticed is that the conclusion contains conditional reasoning: Driving a large car (rather than small car) less likely to be injured in an auto accident. Since this is a "weaken" question, I want to focus on the necessary condition.

Choice (A) has a null effect on the necessary condition; the conditional relationship does not deal with speed.

Choice (B) has a null effect on the necessary condition; the answer does not address accidents or injuries.

Choice (C) has a null effect on the necessary condition; the conditional relationship does not deal with medium- sized cars.

Choice (D) does attack the necessary condition because although the stimulus said that there were fewer injuries for those in large cars, nothing is mentioned about the likelihood of being in an accident for small cars versus large cars. If the likelihood of being in an accident were the same for a small and a large car, the conclusion would make sense. However, if large cars are more accident- prone than small cars, that would call into question the conclusion. It's not a strong attack on the conclusion but it does weaken it to a degree.

Choice (E) has a null effect on the necessary condition; there is no mention of car size related to the accidents or injuries.

Is my thinking correct here?

This looks great to me! Good work.

I don't think the conclusion is making any claims about "overall" risk! It's referring to injuries on a "per accident" basis.

For example, "How far can this car travel maximum in an hour?" is the same as asking "how far maximum can this car travel per hour?"

The conclusion is actually sound from my perspective, which is very upsetting as a test taker :S

[Adam Tyson]

I get your frustration, Dianapoo. The authors of this test are good at causing confusion, and can be infuriating at times. But, they are at all times fair, and the right answers are right for a good reason. Because of that, we can, with effort, parse through the language and get to the right answer.

The key to this stimulus is the placement of the word "if" in the conclusion. "If one drives a large car" means driving the car is sufficient, and what is necessary is a higher chance of being injured in an accident. This would be entirely different if the conclusion was "if you are in an accident, you are less likely to be injured in a large car." There, being in an accident is the sufficient condition.

Consider this statement:

"If you live in Kansas, you are unlikely to be injured by an alligator attack."

This seems reasonable, because alligators aren't roaming around Kansas attacking people. Now, compare that to this:

"If you are attacked by an alligator, you are unlikely to be injured in Kansas."

This is, of course, nonsense - being in Kansas will not protect you from injury should an alligator attack you there. Those chompers don't care where you are!

So, to our conclusion: if you drive a large car, what are the odds of being injured in an accident? It depends on the odds of being in an accident in the first place, and then on the odds of being injured in that accident. The odds of getting injured increase dramatically if the odds of being in an accident go way up, and they go down to zero if the odds of being in an accident go to zero. That's why we are analyzing this argument as being about the overall risk of being injured, rather than on the odds of being injured only if you are in an accident - the "if" tells us to do it that way.

One thing I have learned in dealing with this test, and that is that it's never worth it to get into an argument with the answer choices. Sometimes I get incredibly frustrated (the "flying dinosaurs" question from June 2018 still bugs the heck out of me), but I know that ultimately the right answer is right for a good reason, and I just have to figure it out. Try revisiting this question, and any others that you find particularly maddening, after a long break, and go after them with the mindset of "I'm going to figure this out" instead of looking to make it wrong. You'll get there!

Stay positive! Keep up the good work!

(Now I think I am going to read that flying dinos question again. Darn it, I am going to make sense of it eventually!)

[okjoannawow]

Sorry to ask a question on a thread that's been replied to so much.. I just wanted to reiterate to make sure I've got the right thinking. A cannot be the right answer because the argument had nothing to do with speed. C cannot be the right answer because it's out of scope (argument didn't mention medium-sized cars at all.) I originally selected C because I thought it skewed the data, thus making the argument invalid.

[Brook Miscoski]

Okjoannawow,

Yes--it's a long thread, isn't it! But you're concerned with the best question--how do you efficiently and correctly process this type of stimulus and question.

Here, we know very little about the proportion of small car drivers to large car drivers in that 10,000 sample, so in a sense we don't know whether the data is "skewed" towards one group or the other. Choice (D) addresses that fairly directly. Choice (C) fails to address it because the proportion of medium cars tells us nothing about large cars versus small cars, which is the comparison we are trying to evaluate. So you were on the right track but simply were not careful enough in seeing which choice spoke best to your correct assessment.

[ArizonaRobin]

Sorry to ask a question on a thread that's been replied to so much.. I just wanted to reiterate to make sure I've got the right thinking. A cannot be the right answer because the argument had nothing to do with speed. C cannot be the right answer because it's out of scope (argument didn't mention medium-sized cars at all.) I originally selected C because I thought it skewed the data, thus making the argument invalid.

I have observed that the LSAT writers often throw in other categories of things when the argument revolves around comparison between two things. In this case, even if half the drivers were in medium sized cars, that still leaves 5,000 cars that were either large or small that the author is discussing. It's irrelevant because the argument isn't about medium sized cars. The argument hinges on a comparison of how safe drivers are in large vs small cars. I consider these to be distractor answer choices that can be attractive because we are accustomed to looking for an alternate cause answer choices in causal arguments. But this isn't a causal argument. We are looking to weaken the comparison between safety in the two cars that the author is focused on.

[Robert Carroll]

ArizonaRobin,

You're 100% right about this point - because the argument is comparing safety of large vs small cars, the fact that other sizes existed just does not matter. Yeah, the argument might only be talking about SOME, not ALL, cars, but...that's what it wanted to do! And it used evidence comparing large and small to prove a conclusion comparing large and small. Medium sizes don't matter for that.

I don't think the discussion of causality is perfect, but it's a good point - the major problem with the stimulus and the problem answer choice (D) exploits is one of numbers and percentages, NOT causality.

Robert Carroll