Verbal questions from any Manhattan Prep GMAT Computer Adaptive Test. Topic subject should be the first few words of your question.
SaifulI24
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Negation test

by SaifulI24 Mon May 03, 2021 11:37 pm

The headmaster at Leawood Day School noticed that scores on math tests were lower this year than in previous years. This year, all students took math courses during the first period of the school day; in years past, they had taken math during the final period of the day. Reasoning that the students perform better on math tests when they are fully awake, the headmaster concluded that test scores would be higher if math classes were moved to the end of the day.


The headmaster’s reasoning depends upon which of the following assumptions?

(A) It would be possible to reconfigure the school’s schedule to accommodate having math classes in the afternoon.
(B) Several schools similar to Leawood Day School hold math classes in the afternoon.
(C) The quality of the teaching has little bearing on test scores.
(D) This year the math department started using new, unfamiliar curricular materials.
(E) Students are more likely to be fully awake during the final period of the day than they are during the first period of the day.


Hello,

In the above problem the answer is E. I understand why, but I have trouble eliminating C. If you negate it, it basically says that the quality of teaching has a great bearing on test scores. This would provide an alternative explanation and thus breakdown the conclusion. Please help clarify.
esledge
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Re: Negation test

by esledge Mon May 10, 2021 1:16 pm

Two things help me: (1) On the Negation Test, do the least extreme negation possible, and (2) reference/say to yourself the exact words of the conclusion as you evaluate the effect of negating the choice.

The exact words of this conclusion are “test scores would be higher if math classes were moved to the end of the day.” We'll come back to this.

For example, let’s look at (E), the right answer.
Most extreme negation of (E): Students are (definitely) less fully awake during the final period of the day than they are during the first period of the day.
Least extreme negation of (E): Students are less likely to be fully awake during the final period of the day than they are during the first period of the day.

Even with the least extreme negation of (E), the conclusion that “test scores would be higher if math classes were moved to the end of the day” suffers; if students are less likely to be fully awake during math class, that would be bad for test scores. Of course, the conclusion suffers even more from the most extreme negation of (E). Thus, (E) is a necessary assumption.

On (C), I think you are doing the most extreme negation, which illustrates whether (C) could impact the conclusion. Test the least extreme negation to evaluate whether (C) actually must impact the conclusion.

Least extreme negation of (C): The quality of the teaching has some (or a non-negligible) bearing on test scores.

It could still be true that “test scores would be higher if math classes were moved to the end of the day” because both teaching quality and time of day for class could affect scores; it is still fair for the argument to claim that time of day for math class affects test scores. I’d argue that even if “the quality of teaching has a great bearing on test scores,” as you say, the presence of one cause doesn’t imply that a second cause is impossible.

Doing the least extreme negation makes it more clear when a choice doesn't actually affect the conclusion. This allows the Negation Test to do its job: eliminate answers that don't necessarily matter to the conclusion.
Emily Sledge
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