#6 - Although this bottle is labeled "vinegar," no fizzing

[Administrator]

Complete Question Explanation

Flaw in the reasoning. The correct answer choice is (B)

The author of this stimulus describes two substances—some liquid in a bottle and some powder from a box, which are labeled "vinegar" and "baking soda," respectively. The author then describes an experiment, in which the liquid from the bottle is mixed with the powder from the box, producing no fizz. The stimulus then describes what should happen when vinegar and baking soda are mixed—fizzing. The author concludes that because there was no fizzing when the two substances we have are mixed, then it must be that the substance in the vinegar bottle has been mislabeled.

An obvious pre-phrase would be that perhaps it was the powder in the box that was mislabeled, rather than the liquid in the bottle, as the stimulus concludes.

Answer choice (A) The stimulus does not ignore this possibility; in fact, this very possibility is a focus of the conclusion.

Answer choice (B): This is the correct answer choice. It matches our pre-phrase, albeit generally: The alternative explanation is that the powder was mislabeled. The stimulus fails to rule out this possibility to explain the observed effect—no fizzing. Since this answer choice accurately describes what happened in the stimulus—without error—this is the right answer.

Answer choice (C) The meaning of the word "fizz" never plays an important role in the stimulus, and hence, it cannot be said that the stimulus depends on its use.

Answer choice (D) This answer choice introduces a whole new concept—that of scientific principles. The stimulus never deals with scientific principles, but rather with the prospect of mislabeled bottles.

Answer choice (E) The stimulus never describes an intention to deceive, so this cannot be the correct answer choice.

[ccude9]

Quick question regarding the verbage used in an answer choice...

The flaw in the question is a false dilemma when it fails to identify other alternatives for the stated effect.

The answer reads: Fails to EXCLUDE an alternative explanation for the observed effect.

In my mind, I read this as a double negative which would imply the stimulus did provide an alternative explanation... Why does the answer choice not state that it fails to INCLUDE?

Because the stimulus does not INCLUDE an alternative explanation, thus yields the flaw.

Please help me understand.

Thank you!

[Adam Tyson]

Good question, ccude. I'm not sure I would classify this one as a false dilemma, as it doesn't set us up with "it's not this, so it must be that." Rather, I think this one falls more into the general category of a flaw in the use of evidence. Perhaps a general lack of relevant evidence? The problem, as with many flaw questions, is that the author has made an unwarranted assumption. He has assumed, without providing justification, that what is in the box is in fact baking soda. He has failed to include that very important piece of information, leaving open the possibility that the vinegar bottle is correctly labeled and that something other than baking soda is in the box. That is the alternative explanation that he failed to exclude.

How might he have done that? On the LSAT, it could have been as simple as "it is known that the box did contain baking soda."

I suppose there may be yet another explanation - both boxes were props in a play, and while they did not contain what they claimed, they were not, technically, mislabeled. I think you would have to have a background in the theater to think of that one!

Either way, by considering only one possibility and failing to rule out others, he has made an evidentiary flaw.

Hope that helped!

[vbkehs]

Reading the previous question and Adam's explanation above doesn't resolve the wording of the correct answer choice for me. Can someone please clarify why the answer choice doesn't read "fails to include an alternate explanation" and instead reads "exclude"? Thank you!

[Adam Tyson]

Sure thing, vbkehs! That's because the if the author wanted his argument to be valid, he wouldn't INCLUDE another explanation, but would rule it out! He should have excluded that possibility by proving it wasn't true - the box DID have baking soda, so it could not be the case that it didn't have it.

Put another way, a good argument doesn't include an alternative to your conclusion. You don't say "X must be true, although maybe it isn't and there is some other explanation." Rather, a good argument excludes that alternative. You say "X is true, because the only possible alternative is definitely NOT true."

The other should have ruled out - excluded - the possibility that the box was not labeled correctly. He failed to exclude that alternative, and that was his mistake.

[vbkehs]

I get it now. Thanks, Adam!

[cd1010]

Hello -- I got the correct answer, but I wanted to clarify why D is wrong. Outside knowledge aside, I was wondering if poor testing conditions could count as an alternative explanation, which is what B is saying. Can you clarify why D does not fall under the umbrella of B? But also, is that not the right line of questioning to cross out D? The official explanation says D introduces a whole new concept, but I wasn't sure why the fact that it's new concept is the thing that's wrong with it? Thank you!

[Robert Carroll]

cd1010,

Answer choice (D) is simply saying something we have no reason to think is true. There is no common-sense reason to think that scientific principles require controlled laboratory conditions. The answer isn't saying that poor conditions might have affected the result. It's saying that nothing could be proven outside the lab. I don't think that's true in general, so it's a bad answer.

Robert Carroll