这题怎么看都不可能是A啊，求解释！！！

squallds

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 fund-raisers 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?

• ASmithtown University's fund-raisers were successful in their contacts with potential donors who had never given before about as frequently as were fund-raisers for other universities in their contacts with such people.  分析A选项
• BThis 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.  分析B选项
• CThis 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.  分析C选项
• DThe 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.  分析D选项
• EMore than half of the money raised by Smithtown University's fund-raisers came from donors who had never previously donated to the university.  分析E选项
  

squallds

我认为A答案并没有加强论证，原因如下：
场景1：frequency = ratio

假设S学校的fund-raiser contact了100个potential donors, 根据题干，其中80%（也就是80个）donors捐了款。
同样假设另一典型学校T的fund-raiser contact了300个potential donors (或者其他任意数量），根据题干，其中小于80%（因为80%被认为exceptionally high）的donors捐了款。
现在，让我们看看A选项：S和T（典型学校）联系没有捐过款的人的频率（即比率）相当，假设40%（或者其他做任意比率），那么我们看到：
S学校联系的100人中，40来自没捐过款的，另外60来自捐过款的，而由于捐过款的再次捐款的概率更高（premise）,如果60捐过款的人中有54个再次捐款（90%），则另外40人只有26个捐款（65%）；
再看T学校，300人中，120来自没捐过款的，另外180来自捐过款的，我们假设这180个捐过款的同样有90%再次捐款，则剩下120人中捐款者的比率必须<65%，才能使总的捐款人数比率低于80%。
所以，很明显T学校对未捐过款的人的筹款效率要比S低，从而反驳了题干的结论。

场景2：frequency = rate or number of donors contacted
同样假设S学校40没捐过款，60捐过款；由于T学校花更多时间在没捐过款的人身上，同样是40个没捐过款，但只有30个捐过款的。
同样假设S学校的成功筹款率分别为65%和90%，T学校由于总的成功率低于80%，即使30个为90%，另外40个的成功率未必会高于65%，因为具体的成功率不清楚。
在这种情况下，A选项既不能加强也不能减弱。

squallds

自己顶一下

zzx576122628

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 fund-raisers constantly try less-likely prospects in an effort to expand the donor base. The high success rate shows insufficient canvassing effort.

前提果：捐款率高达80%，但是许多捐款人都是旧的捐款人，募集捐款的人同时还在开拓新捐款人
结论因：高捐款率表明筹集捐款的努力很无效
加强

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 fund-raisers forother universities in their contacts with such people.  联系了那么多次还拉不到捐款这不就是努力无效么，涉及了“果”中的潜在捐款人的特点，加强因果联系
• 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. 今年新捐款人的平均捐款数目比去年总的平均捐款数目多，不涉及因果
• 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. 今年老的捐款人捐款的时候都没有被募集捐款的人联系过，可是他们还是捐了，不影响结果
• 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.  大部分的募捐捐款的人拿来的钱都是新进来的钱，那就是他们的工作有效啊，削弱
• 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. 这个选项跟C一样啊
  

zzx576122628

squallds 发表于 2014-8-13 01:19
我认为A答案并没有加强论证，原因如下：
场景1：frequency = ratio

额题主，你的假设“假设S学校的fund-raiser contact了100个potential donors, 根据题干，其中80%（也就是80个）donors捐了款。”真的合理么，你怎么知道他们没有联系过老的donors，题干那句话“good fund-raisers constantly try less-likely prospects in an effort to expand the donor base”貌似是说他们怎么怎么扩大基础但是不表明他们只找了潜在的人啊，也许一边联系旧爱一边找新欢呢？只要新欢多余旧爱那就是基础大啊，你的假设我觉得有问题，就没向后看

ChenLuAda

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 fund-raisers constantly try less-likely prospects in an effort to expand the donor base. The high success rate shows insufficient canvassing effort.

fact1：80%donation来自potential donor contacted,this rate is exceptionally high.
fact2: people most likely to donate are those who have donated in the past .
conclusion:这么高的成功率不是因为sufficient canvassing effort to expan the donor base.而是因为potential donor多是以前捐过的。
key：在拓展新的捐赠人中，并没有突出表现。

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 fund-raisers for other universities in their contacts with such people.     对于从没有捐赠过的人，Smithtown成功联系到捐赠的比例和其他学校的的fund-raisers一样------>insufficient canvassing effort to expand the donor base.作为food fun-raisers，他并没有有突出于其他学校的canvassing的优势。

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.      Smithtown大学自己的过去跟现在对比，比较的还是size of donations.（无关），因为逻辑中强调的应该是donor base，注重新的捐赠者.

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.             之前捐过钱，今年又来Smithtown捐款的人并没有接到电话，是自己来的。（无关），强调的是老的捐赠者，如果这题是说maintain donor relationship则比较相关。

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.      weaken conclusion的作用。

EMore than half of the money raised by Smithtown University's fund-raisers came from donors who had never previously donated to the university.       同B，关注的是money的数量，而不是number.即使相关，也weaken conclusion.