GWD-10-29

xjtufu

捐款人有两类：处女捐和非处女捐
看A项，大家的处女捐相等，但是某大学比例高达80%，肯定非处女捐严重超标。。。

lllmmm

这题正确答案是A

xiaoshou523

我也同意选A,robertchu分析得很透彻,精彩!
但A中还有个不爽的地方,题目结论说的是insufficient canvassing effort.是负评价.但按A的说法,至少他们在游说以前从没有捐款的人士的效果与其他大学的一样,而对已捐过款的人士的游说效果比其他学校好,(因为他们总体的成功率80%是较高的).这样的努力怎么也不能落一个负评价呀!
除非答案中暗示SU的游说人员在游说以前从没捐过款的人士的态度没有其他学校的积极才应该说他们insufficient canvassing effort,
所以还是觉得A牵强.

-- by 会员 jackylin76 (2004/7/19 2:45:00)

恩 我错选C就是认为A中没有说明他们做的不好，只说他们做的不是比别人好。受了原文中insufficient的影响，以为要找负评价呢！！

xyc19901015

我个人认为这题的关键并不是C会削弱或者增强argument，而是在于C中This year most of the donations that came to Smithtown University from people who had previously donated to it were made without the university’s fund-raisers having made any contact with the donors.的  WITHOUT make any contact 说明了这个选项与讨论Smithtown University’s fund-raisers 到底是在挑软柿子捏还是spare no effort to expand the donor base均是无关的，这仅仅是描述了一个事实而已。而A对就对在讨论的是Smithtown University’s fund-raisers 在canvass effort中与其他fund-raisers的比较

m0n1caa

原文：S大学的募款人从已联系过的人当中得到的捐款比例是80%  也就是说：在他们联系过的人当中，有80%来捐款了
        但是，这么高的比例不能说明 fund-raisers did a good job  
        [潜在含义是：如果这些捐款人中全是之前曾捐过款的人 那么说服他们捐款很容易  也就是说：fund-raiser没有使劲儿干活]

       而 good fund-raiser 通常是跟从未捐过款得人联系  以此扩宽捐款人的基数 （expand the base）

      得出结论：high success rate --> insufficient canvassing effort

选项：要证明 -- 80%里包括很多已捐过款得人     【如果80%里包括很多没捐款的人-> expand the base --》good job --》weaken】

A.   S大学与从未捐过款的人的联系情况与其他大学差不多（或者说S大学与从未捐过钱的人的联系频率与其他大学差不多） 也就是说：那80%的高比例高在已
  捐款的人又来捐款 --》 support

BDE  新捐款人捐款比例大 或者 新捐款人比老捐款人人数多 等等 --》 expand the base --> weaken

C. 大多数来捐款的人都是以前捐过钱的人  并且这些人不在fund-raiser的联系名单内
  也就是说：fund-raiser联系的大多是以前没捐过钱的人   那么能在没捐过钱的人当中获得80%的捐款率 说明 他们did good job --》 weaken

mxzhcx

想想还是该选C吧。
不用很复杂的分析。
A里说S和其他学校联系potential donar 让其捐款的成功率是一样的。 但是有可能A联系了10个donar，成功了8个。别的学校联系了100个 成功了80个。这并没说明A的80%就比人家好。
C是无关选项。 说了大部分的捐款都是没联系就来捐的老客户，但这个跟80%的成功率一点关系也没有。因为80%说的是S联系了的新客户。因此与其是否工作做得好无关。 而且就算大部分的捐款都来自老客户，也有可能新客户的80%代表一个很强的工作能力（有可能一堆新客户捐的钱很少，但是确实有很多新客户来，这说明工作能力强），也可能80%代表一个很弱的工作能力。（比如只有一两个公司却捐了很多钱）。这些都是不定的。因此C项根本不能说明80%的意义。

babybearmm

我觉得这题画个逻辑简图就很简单了啊

Conclusion. SU not good fundraiser
Premise 1. (fact) SU high successful rate
Premise 2. good fundraiser try less-likely-donors

由Premise 2. 作者潜在的含义是：
for good fundraiser: try many less-likely-donors <------> low successful rate
可以看出，作者推出conclusion基于的直接assumption是：
ASSUMPTION: high successful rate <-------> not try many less-likely-donors (in this sense, not good fundraiser)
这就是assumption，说白了，就是把"successful rate"和"try less-likely-donors"架桥。

于是我们进行prephrase，推测正确选项应该是validate this assumption.

那么A，就是明显满足。A干的事情，在科学研究上叫做control，将其他条件的影响限定为0。A说的是，在less-likely-donors这部分pool里，SU和别的学校的successful rate相等。

如果同学认为以上control的概念不是那么straightforward，我再用数学公式来解释
咱要讨论的"successful rate"是overall successful rate，设为r
分为两个sample pools:
Pool 1. less-likely-donor     设success rate为 r1       这部分人占的比例x%
Pool 2. more-likely-donor     设success rate为 r2      这部分人占的比例(100-x)%
条件r1<r2
r=r1*x% + r2*(100-x)%          

作者的逻辑是：r大，就证明x小（r2那一项的“比重”大），也就是说not good fundraiser
但是

式的变量太多，决定r的变量，除了x之外，还有r1, r2.
当r1, r2恒定的时候，基于r1<r2，我们从逻辑上可以完美推出r和x之间的关系，如作者所述(r大，则x小)。
所以，A选项干的事情，就是令r1恒定("were successful ... as frequently as")。

C is totally out-of-scope.
以上讨论的范围是那些have been contacted的人（分为less-likely-donor和more-likely-donor两部分），C说的是关于people not having been contacted. 所以out-of-scope.

Smithtown University’s fund-raisers succeeded in getting donations from 80 percent of the potential donors they contacted. This success rate, exceptionally high for university fund-raisers, does not indicate that they were doing a good job. On the contrary, since the people most likely to donate are those who have donated in the past, good fundraisers constantly try less-likely prospects in an effort to expand the donor base. The high success rate shows insufficient canvassing effort.

Which of the following, if true, provides more support for the argument?

A. Smithtown University’s fund-raisers were successful in their contacts with potential donors who had never given before about as frequently as were fundraisers for other universities in their contacts with such people.

B. This year the average size of the donations to Smithtown University from new donors when the university’s fund-raisers had contacted was larger than the average size of donations from donors who had given to the university before.

C. This year most of the donations that came to Smithtown University from people who had previously donated to it were made without the university’s fund-raisers having made any contact with the donors.

D. The majority of the donations that fund-raisers succeeded in getting for Smithtown University this year were from donors who had never given to the university before.

E. More than half of the money raised by Smithtown University’s fund-raisers came from donors who had never previously donated to the university.

The given key is C, but I think A is better.  What do you guys/girls think?  Thanks in advance!

-- by 会员 robertchu (2004/7/1 3:36:00)

babybearmm

我现在做逻辑题的思路都是先理清题意抽象成逻辑或者数学模型，就跟解应用题一样，这样就避免自己被那些很复杂的语言绕住，因为数学公式对我来说很straightforward. 所以那道题我的解释就是纯数学，control的概念：

目标：研究变量(variant) x和变量y的关系
(x is called an independent variant; y is called a dependent variant. )
我们知道y=f(x, a, b, c, ....)                  y is a function of x, a, b, c, ...
那么就需要令a, b, c, ...统统恒定，变成常量(constant)，这样就是：
y=f(x)

以上是这道题的逻辑基础，或者数学基础，想明白了就特简单。

babybearmm

发现一道跟这题很像的Manhattan CAT题目：

Smith, a basketball player, successfully made 80% of the shots that he attempted this year – an exceptionally high percentage for a player in Smith's league. However, this statistic does not mean that Smith is an exceptional shooter, because the best shooters take many shots from risky locations 20 or more feet away from the basket. Instead, Smith's high shooting percentage simply shows that he takes most of his shots from locations very close to the basket.

Which of the following statements, if true, provides additional support for the argument?

		Smith's shooting percentage for shots taken from more than 20 feet away from the basket is no higher than other players' shooting percentages from that distance.
		Smith took most of his shots during games that were closely contested and in which his team could not afford the time and effort to set up easier shots.
		Very few of the baskets scored by Smith's team from locations close to the basket were shot by Smith himself.
		The position that Smith plays allows him relatively few shooting opportunities from locations close to the basket.
		Smith's shooting percentage, the highest in the league, was almost 10% higher than that of the player with the next highest percentage.

babybearmm

发现一道跟这题很像的Manhattan CAT题目：

Smith, a basketball player, successfully made 80% of the shots that he attempted this year – an exceptionally high percentage for a player in Smith's league. However, this statistic does not mean that Smith is an exceptional shooter, because the best shooters take many shots from risky locations 20 or more feet away from the basket. Instead, Smith's high shooting percentage simply shows that he takes most of his shots from locations very close to the basket.

Which of the following statements, if true, provides additional support for the argument?

		Smith's shooting percentage for shots taken from more than 20 feet away from the basket is no higher than other players' shooting percentages from that distance.
		Smith took most of his shots during games that were closely contested and in which his team could not afford the time and effort to set up easier shots.
		Very few of the baskets scored by Smith's team from locations close to the basket were shot by Smith himself.
		The position that Smith plays allows him relatively few shooting opportunities from locations close to the basket.
		Smith's shooting percentage, the highest in the league, was almost 10% higher than that of the player with the next highest percentage.

-- by 会员 babybearmm (2012/7/10 15:50:28)

The principal issue in the argument is the interpretation of Smith's 80% shooting percentage. The argument indicates that this is an “exceptionally high percentage” but attributes that percentage to shots taken from positions closer to the basket – that is, easier shots. To strengthen this argument, additional information is required that points to the fact that Smith did, indeed, achieve his high shooting percentage as a result of taking easier shots (closer to the basket). Alternatively, information showing that Smith is no better than other players when shooting from the risky, far away locations (more than 20 feet from the basket) would serve the same purpose; if that were true, then Smith's superior overall shooting percentage would necessarily result from a higher rate of making easier shots.

(A) CORRECT. According to this choice, Smith's percentage on risky (more than 20 feet from the basket) shots is no better than that achieved by other players from the same distance. If this statement is true, then the only possible source of Smith's higher overall percentage is a superior contribution from easier shots. This choice therefore strengthens the argument.

(C) This choice suggests that Smith did not, in fact, preferentially shoot easy shots from close to the basket; in fact, it indicates the opposite. If Smith took very few of his team's close shots, then the claim that his shooting percentage is based largely on such shots is implausible. Therefore, this option weakens the argument.