#11 - A science class stored one selection of various fruits

[Administrator]

Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (C)

The flaw in this argument is an overgeneralization based on limited evidence. This type of error in the use of evidence can be difficult to identify, because it requires you to look beyond the data points provided to see where a problem might occur.

The science class discussed in the stimulus conducted an experiment testing how long various types of fruit stay fresh at various temperatures. The class stored three selections of various fruits, each under similar conditions, except that each of the three selections was stored at a different temperature: 30 degrees Celsius, 20 degrees Celsius, and 10 degrees Celsius respectively. The result of the experiment was that the fruits stored at 10 degrees Celsius stayed fresh longer than those stored at 20 degrees Celsius, which stayed fresh longer than those stored at 30 degrees Celsius. From this result, the class concluded that the cooler the temperature at which these varieties of fruits are stored, the longer they will stay fresh.

The class’ conclusion was expansive, in that it places no limit on how low the temperature can go while extending the length of time the stored fruit will remain fresh. While the evidence provided three separate data points, the three temperatures tested in the experiment, there is no evidence to support the conclusion that the correlation between decreasing storage temperature and longer lasting freshness is infinite.

Answer choice (A): While the conclusion does make an impermissible generalization, it does not generalize from one type of fruit to another. In fact, the conclusion expressly refers to “these varieties of fruits.”

Answer choice (B): The premises establish that the experiment took the effects of other factors into consideration, because it stored each selection of fruit in “similar conditions.” While the stimulus does not expressly state what those conditions were, it clearly indicates that the class recognized that conditions other than temperature were also relevant to the rate of spoilage.

Answer choice (C): This is the correct answer choice. From information regarding a set of only three temperatures, the class concludes that at all temperatures the relationship between temperature and the spoilage of these varieties of fruits will remain the same: the lower the temperature at which they are stored, the longer they will stay fresh.

Answer choice (D): The reasoning that you must assess in a Flaw in the Reasoning question is the connection between the premises and the conclusion. You can only take the facts as given and determine the validity of the conclusion from those facts. Here, there is no reason to think that the class assumed without proof that its thermometer was reliable, and such an assumption would not impact your assessment of the conclusion. It is not your task to assess the truth of the conclusion, but rather its argumentative validity.

Answer choice (E): This answer choice is inconsistent with the stimulus. The class offered the relationship between lower temperatures and the lasting freshness of the fruit as the explanation for the results of its experiment.

[maximbasu]

Hello,
I chose B as the correct answer while the correct answer was C.

I understand C; it's stating that other temperatures below/ above may not correspond with the general trend the class came up with. Why is B wrong?
B seems to give alternative explanations for some of the factors that could have influenced the freshness of the fruits.


Thank you, Maxim.

[Emily Haney-Caron]

Hi Maxim,

The reason B is wrong is that it doesn't provide a possible explanation for the difference outcomes for these fruits. The stimulus tells us that all three selections of fruit are stored "in similar conditions," which indicates that nothing varied substantially other than the temperature. As a result, temperature is the explanation for the difference; the problem is related to the range. Does that help?

[MelinColorado]

Hi Emily,

I actually chose answer choice B, but I did understand that other factors mentioned were held constant for the sake of the experiment. The reason I chose B was because the conclusion does NOT state that these factors will be held constant in the future--it simply states that the cooler the temperature at which fruits are stored, the longer they will stay fresh. The conclusion DOES seem to ignore the effect of other factors such as humidity, sunlight, etc--for example, an apple stored at 30 degrees stored in darkness might stay fresh longer than an apple stored at 10 degrees but kept in direct sunlight. In this case, the fruit stored at the cooler storage temperature would NOT stay fresh longer. (Thus a hole in the conclusion's reasoning.) Can you straighten me out? Thanks!

[Kristina Moen]

Hi Melin,

You are totally right to question if conditions were different for the various fruits in the study. Whenever you see a conclusion based on study, you should be asking yourself that! If indeed conditions were different, then it might not be the temperature that is causing the fruit to stay fresh. That issue is often a flaw, a way to weaken or strengthen an argument, or an assumption. It's a good thing to spot.

The test writers addressed this potential flaw in the stimulus. Re-read the first part of the stimulus
"A science class stored one selection of various fruits at 30 degrees Celsius, a similar selection in similar conditions at 20 degrees, and another similar selection in similar conditions at 10 degrees."

Upon re-reading your question, I can see that you understood this. However, I'll leave the explanation here for future test takers.

The conclusion is not that every fruit that is stored at 10 degrees will stay fresher than every fruit stored at 30 degrees. The conclusion is about causation. The cooler the temperature, the fresher the fruit will last. One specific fruit in one specific condition. So yes, of course if you bruised a fruit or took a slice out of it (or any other thing you could do!), it might not be very fresh. But the conclusion is that temperature is a factor. It doesn't say it's the only factor. Hope that helps!

[queenbee]

Hi
I agree with the comment about B, but selected it over C because said the temperature ranges were too narrow. I am not clear on what the question considers narrow. 10 C = 50 F, and, 30 C = 86 F. That is a 36 degree temperature range. Why is that considered narrow?

Also - i thought that the duration under that specified conditions and temperature could have been a factor, which led me to lean on B even more.
Would you please help with this?
Thanks

[Robert Carroll]

queenbee,

The situation in the stimulus is one of overgeneralization. If I say "Two of my friends were shortchanged at that store, so some people get shortchanged at that store," that's not an overgeneralization - to prove that "some" people had something happen to them, I only need to show that it happened once. But if I say "Two of my friends were shortchanged at that store, so everyone gets shortchanged at that store", I now increased the breadth of my conclusion to include everyone, and now a premise about two people won't be broad enough to encompass the conclusion.

So whether a conclusion is overbroad depends on how broad the premises are in relation to that conclusion. If the argument in this stimulus had concluded "Cooler temperatures will sometimes affect how long these varieties of fruits stay fresh," I'd see less of a problem here. At a certain range of temperatures, that was true, so it's sometimes true. The conclusion is not so qualified, though - it's saying that, without qualification, cooler temperatures will lengthen the freshness timeframe of these fruits. Not knowing anything about the information about the entire range of temperatures IS a problem for that conclusion - we actually do need to know what would happen at more temperatures than those listed. That's why the premises are too narrow for the conclusion - because the conclusion is about all temperatures.

As mentioned before, answer choice (B) is not correct because the stimulus is holding other conditions besides temperature constant. It's not ignoring those other conditions - it's trying to abstract way from them to consider just temperature. No one in the stimulus is acting like those other conditions couldn't affect freshness.

Robert Carroll