#10 - Columnist: The failure of bicyclists to obey traffic

[LAM]

Thanks Adam. I like your analogy about PB&J.

[avengingangel]

wow @ this question. i just read thru all of the replies and think i may be more confused? could someone just tell me if this is the correct thinking here in why c is correct as the flaw?: is it bc the columnist fails to consider that the 1/4 bicycle-caused accidents & the "more than 1/4" safety equipment-caused accidents could all be partial causes of the SAME accidents?? they're not necessarily 2 DIFFERENT quarters of the whole 100% of accidents.

[James Finch]

Hi AA,

You've hit the nail on the head. The issue in the stimulus is that the Columnist assumes that failure to obey traffic regulations was never a factor in the accidents in which inadequate safety equipment was a factor, and vice versa, without justification. In reality, the overlap between the two could be anywhere from 0-100%, meaning the actual percentage of accidents in which bicyclists are partially responsible is anywhere from "over 25%" to "over half."

[harvoolio]

Frustrating. I pre-phrased a different flaw and did not recover when the flaw was not the one identified.

I thought the reasoning assumes that the use of "inadequate bicycle safety equipment" means bicyclists are partially responsible. Assume you drive a car that is later discovered to have faulty INSERT WHATEVER does that mean you are responsible. Did I approach this incorrectly given the question was not an assumption question, but a flaw question and I identified a necessary assumption rather than a reasoning flaw?

Thanks.

[Adam Tyson]

Actually, harvoolio, you accurately identified a second flaw in the argument, which could have led to a good answer choice. The author here DOES assume that bicyclists are at least partially responsible for some of the problems with inadequate equipment, either because they aren't choosing the good stuff or not using it properly, etc. Perhaps the problem is faulty equipment that is not the responsibility of the cyclist, but of the manufacturer? Yes indeed, that is an unwarranted assumption here! BUT, the numbers/percentages problem is still a problem, as there is no evidence to suggest that the two groups are distinct, but could overlap, and if they overlap even a little that might ruin the argument.

When your prephrase doesn't get you a good answer choice, reset and try again, and be on the lookout for common flaws. When a stimulus brings up numbers and percentages in the premises, be on high alert for problems with numbers and percentages in the conclusion! That happens too frequently on the LSAT for us to overlook it. A question can have many flaws, and you need to be ready to identify any of them at any given time!

[msegarra]

I prephrased the correct answer. However, there is one thing that irks me about this problem. The columnist makes a causal claims. In reality, you wouldn't be able to make causal claims about a issue such as this because you don't have the setup for it. Claiming causality can only be done under certain conditions like a randomized control trial, which, of course, a study on accidents wouldn't be able to do. Therefore, you could only point out the correlation in a study. While I knew that the answer would be C, it still bothered me to choose it knowing how flawed that causality statement is. Are we to assume that anything explicitly stated in the stimulus of a flawed question type will be taken at face value?

[Rachael Wilkenfeld]

Hi msegarra,

That's an important thing to note about causal reasoning on the LSAT. It's pretty much always flawed! They don't provide the necessary information to prove the causal relationship. We are always on the look out for alternate causes, instances where the cause occurs but not the effect, and other possible issues with the causal relationship proposed.

However, in this question, they don't really need to deal with any of this. Even if we accept the causal explanations for each accident, we have a problem with the conclusion drawn from those explanations. Even if more than 1/4 of bike accidents involve failure to obey traffic regulations, and over 1/4 involve inadequate bike safety equipment, we can't draw the conclusion that bicyclists are responsible for over 1/2 of accidents. We haven't established that the two causes are fully independent. A single accident could have both a bicyclist that disobeyed traffic regulations AND a bike with inadequate safety equipment. In fact, theoretically the more 1/4 that have disobeyed traffic regulations and the more 1/4 that have inadequate safety equipment could be the exact same 1/4.

Hope that helps
Rachael