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- Fri Jan 21, 2011 12:00 am
#27213
Complete Question Explanation
Parallel Flaw. The correct answer choice is (B)
The question stem indicates that there are two logical flaws in this argument. Before proceeding to any of the answer choices, we must clearly identify each of these flaws. The premises are that Professor Donnelly’s exams are always more difficult than Professor Curtis’s exams and that the question about dinosaurs was on Professor Donelly’s exam. According to the argument, this question must therefore be difficult.
In general terms, this conclusion mistakenly assumes that what is true of the whole must also be true of each of the parts and confuses a relative statement with an absolute statement. Because Professor Donelly’s exams as a whole are more difficult than Professor Curtis’s exams does not mean that each question on Professor Donelly’s exams is itself difficult. In fact, Professor Donelly’s exams may be more difficult because of an exam time limit rather than difficult questions. Also, we cannot determine if Professor Donnelly’s exams are truly difficult at all. Unlike this exam, both professors’ exams may be ludicrously easy and Professor Donelly’s exams may be only slightly less easy than Professor Curtis’s exams.
Therefore, the correct answer choice must incorrectly claim that some part of a group has a certain characteristic just because the group as a whole has more of that characteristic than some other group. Only answer choice (B) displays both of these flaws.
Answer choice (A): Since this answer does not conclude that Lewis’ cake must be good, it does not display the second logical flaw discussed above. It does, however, conclude that one of Lewis’ cakes will be better than most of Stockman’s cakes because Lewis is a better baker than Stockman. This is similar to the first logical flaw since Lewis might specialize in baking bread and pastries. In any case, answer choice (A) is incorrect.
Answer choice (B): This is the correct answer choice. Just as Professor Donelly’s exams are more difficult than Professor Curtis’s exams, Porter’s new book of poetry is better than any of her other books of poetry. Of course, this does not ensure that a poem from Porter’s new book is good. The selected poem might be a bad example from a good collection or the entire book may be bad, just not quite as bad her other books. Both of these mistakes match the flaws from the stimulus.
Answer choice (C): This answer does confuse a relative statement with an absolute statement, but not in precisely the same way as the stimulus does. Here, the relative statement in the conclusion (“This year’s English class will have to do more reading than last year’s class”) is erroneously drawn from an absolute statement in the premise (Professor Whitburn “always assigns a lot of reading.”) In the stimulus, the error was reversed. Furthermore, this answer does not contain the first logical flaw.
Answer choice (D): We cannot that the plot of Shield’s first novel is very complex just because it is more complicated than any other novel she has written. This flaw is identical to the second flaw discussed above, but this answer does not make the mistake of assuming that any part of a group has the same characteristic as the group itself.
Answer choice (E): While some students may argue that this answer mistakenly assumes calculus has the same characteristic as mathematics overall, must students probably agree that calculus is a difficult part of mathematics. Either way, this answer does not make an absolute claim based on a relative premise. Also, you should note that this answer choice is about tests and the stimulus is about exams. Any answer choice which addresses a similar subject as the stimulus should be a red flag. Such answer choices are occasionally correct, but they are usually traps for hurried or careless students.
Parallel Flaw. The correct answer choice is (B)
The question stem indicates that there are two logical flaws in this argument. Before proceeding to any of the answer choices, we must clearly identify each of these flaws. The premises are that Professor Donnelly’s exams are always more difficult than Professor Curtis’s exams and that the question about dinosaurs was on Professor Donelly’s exam. According to the argument, this question must therefore be difficult.
In general terms, this conclusion mistakenly assumes that what is true of the whole must also be true of each of the parts and confuses a relative statement with an absolute statement. Because Professor Donelly’s exams as a whole are more difficult than Professor Curtis’s exams does not mean that each question on Professor Donelly’s exams is itself difficult. In fact, Professor Donelly’s exams may be more difficult because of an exam time limit rather than difficult questions. Also, we cannot determine if Professor Donnelly’s exams are truly difficult at all. Unlike this exam, both professors’ exams may be ludicrously easy and Professor Donelly’s exams may be only slightly less easy than Professor Curtis’s exams.
Therefore, the correct answer choice must incorrectly claim that some part of a group has a certain characteristic just because the group as a whole has more of that characteristic than some other group. Only answer choice (B) displays both of these flaws.
Answer choice (A): Since this answer does not conclude that Lewis’ cake must be good, it does not display the second logical flaw discussed above. It does, however, conclude that one of Lewis’ cakes will be better than most of Stockman’s cakes because Lewis is a better baker than Stockman. This is similar to the first logical flaw since Lewis might specialize in baking bread and pastries. In any case, answer choice (A) is incorrect.
Answer choice (B): This is the correct answer choice. Just as Professor Donelly’s exams are more difficult than Professor Curtis’s exams, Porter’s new book of poetry is better than any of her other books of poetry. Of course, this does not ensure that a poem from Porter’s new book is good. The selected poem might be a bad example from a good collection or the entire book may be bad, just not quite as bad her other books. Both of these mistakes match the flaws from the stimulus.
Answer choice (C): This answer does confuse a relative statement with an absolute statement, but not in precisely the same way as the stimulus does. Here, the relative statement in the conclusion (“This year’s English class will have to do more reading than last year’s class”) is erroneously drawn from an absolute statement in the premise (Professor Whitburn “always assigns a lot of reading.”) In the stimulus, the error was reversed. Furthermore, this answer does not contain the first logical flaw.
Answer choice (D): We cannot that the plot of Shield’s first novel is very complex just because it is more complicated than any other novel she has written. This flaw is identical to the second flaw discussed above, but this answer does not make the mistake of assuming that any part of a group has the same characteristic as the group itself.
Answer choice (E): While some students may argue that this answer mistakenly assumes calculus has the same characteristic as mathematics overall, must students probably agree that calculus is a difficult part of mathematics. Either way, this answer does not make an absolute claim based on a relative premise. Also, you should note that this answer choice is about tests and the stimulus is about exams. Any answer choice which addresses a similar subject as the stimulus should be a red flag. Such answer choices are occasionally correct, but they are usually traps for hurried or careless students.
