求助verbal分册一道题目

hoyancyn

谁能帮我解释一下D的分析是什么意思？
63. Traditionally, decision making by managers that is reasoned step-by-step has been considered preferable to intuitive decision making. However, a recent study found that top managers used intuition significantly more than did most middle- or lower-level managers.
This confirms the alternative view that intuition is actually more effective than careful, methodical reasoning.
The conclusion above is based on which of the following assumptions?
(A) Methodical, step-by-step reasoning is inappropriate for making many real-life
management decisions.
(8) Top managers have the ability to use either intuitive reasoning or methodical, step-by-step reasoning in making decisions.
(C) The decisions made by middle- and lower-level managers can be made as easily by using methodical reasoning as by using intuitive reasoning.
(D) Top managers use intuitive reasoning in making the majority of their decisions.
(E) Top managers are more effective at decision making than middle- or lower-level managers.
Argument Construction
Situation    Intuition, used significantly more by top managers than by middle- or lower-level
managers, is found to be more effective than step-by-step reasoning in making decisions.
Reasoning What assumption does the argument make? The study shows that top managers use
intuition more in decision making than the other managers do. The conclusion is then drawn that intuition is more effective. But the stated premises on their own provide inadequate support for the conclusion, so it is reasonable to think that the argument must be based on an unstated assumption, such as the assumption that top managers, when employing intuitive decision making, make more effective decisions than middle- and lower-level managers. Without some such assumption, the argument fails.
A While the argument is consistent with this idea, the inappropriateness of step-by-step reasoning is not assumed.
B Top managers’ ability to switch decision methods does not help to show that one method is better than the other.
C The effectiveness of decision-making methods, not the ease with which the methods are applied, is the subject of the argument.
D The argument would not necessarily fail if something incompatible with this statement were assumed—for example, if it were assumed that top managers use intuition only in half of their decisions. Thus this statement does not have to be assumed. Moreover, even if this statement were to be added as an assumption to the stated premises, the support for the conclusion would still be inadequate unless some additional assumption were made.
E Correct. This is the best choice for the missing assumption. Without some such assumption, the argument would fail.

zhanghaolin

The argument would not necessarily fail if something incompatible with this statement were assumed—for example,
if it were assumed that top managers use intuition only in half of their decisions. Thus this statement does not have to be assumed. Moreover, even if this statement were to be added as an assumption to the stated premises, the support for the conclusion would still be inadequate unless some additional assumption were made.

GMAT官方解释说，intuition is actually more effective than careful, methodical reasoning这个argument不会fail如果假设一些和这个论点无关（imcompatible）的信息。比如，假设最高管理层在做决定时，有50%的概率都是靠直觉。（个人注解：D选项中的majority其实和50%就是差不多的意思，所以GMAT认为D选项的信息是imcompatible和irrelevant的）所以D选项假设不假设都对argument的成立与否都没有影响。

anilolive

Traditionally, decision-making by managers that is reasoned step-by-step has been considered preferable to intuitive decision-making (opposing opinion). However, a recent study found that top managers used intuition significantly more than did most middle- or lower-level managers (premise). This confirms the alternative view that intuition is actually more effective than careful, methodical reasoning (conclusion).

The premise says the top managers used intuition more than most middle- or lower-level managers. The conclusion is that the intuition is mroe effective than methodical reasoning (or step-by-step reasoning).

Necessary assumption. Use negation.

If you negate E), you have:
Top managers are NOT more effective at decision-making than middle- or lower-level managers.
If this is the case, then the method used by top managers are not more effective than the method used by the middle- or lower-level mangers. And from the stimulus, we know that the top managers use intuition significantly more than most middle- or lower-level managers. So intuition is NOT more efficient than the step-by-step reasoning method, which is commonly used by all managers. Thus, the conclusion falls apart.

anilolive

The explanation for D) says:
If you negate D), the conclusion still might hold. Thus, according to the negation method, D) is not necessary.

hoyancyn

谢谢，懂了！

hoyancyn

Traditionally, decision-making by managers that is reasoned step-by-step has been considered prefera ...
anilolive 发表于 2013-4-28 06:40

也就是说这种取非也无法使原文不成立，最多削弱原文吧？

anilolive

Majority = more than 50%.  

Negation: Not more than 50%; could be 50%, 49% . . .0%

TerraceHo

Traditionally, decision-making by managers that is reasoned step-by-step has been considered prefera ...
anilolive 发表于 2013-4-28 06:40

我还是不明白，如果E取非，就得到，高级经理和其他经理在做决策上一样有效，这时加上假设便是，高级经理和其他经理在做决策上一样有效，并且高级经理用intuition比其他经理用的多，这就证明，intuition确实比另一个方法有效。