浅析GMAT非形式逻辑解题方法

1、前后呼应原则

“假设”题型的答案一定是文章成立的必要条件，从形式上分为“桥梁型”和“排除削弱型”。其中的“桥梁型”是直接考察“前后呼应”的，“加强”、“削弱”等题型则是建立在“桥梁型”的基础上。

例1 “On the whole,” Ms. Dennis remarked, “engineering students are lazier now that they used to be. I know because fewer and fewer of my students regularly do the work they are assigned.”

The conclusion drawn above depends on which of the following assumptions?

(A) Engineering students are working less because in a booming market they are spending more and more time investigating different job opportunities.

(B) Whether or not students do the work they are assigned is a good indication of how lazy they are.

(C) Engineering students should work harder than students in less demanding fields.

(D) Ms. Dennis’ students are doing less work because Ms. Dennis is not as effective a teacher as she once was.

(E) Laziness is something most people do not outgrow.

翻译：

丹妮丝女士说：“总的来说，工程系的学生比他们过去更懒了。我知道这一点因为我的学生中做指派工作的越来越少了。”

问：上面的结论基于下面哪一个假设?

(A) 工程系的学生工作越来越少了，因为在一个蓬勃发展的市场中他们花越来越多的时间调查各式各样的工作机会。

(B) 学生是否做指派的工作是他们多懒的一个标志。

(C) 工程系的学生应该比那些要求较低的领域中的学生更加努力工作。

(D) 丹妮丝女士的学生工作得更少因为丹妮丝女士作为老师不象以前那么有效了。

(E) 懒惰是大部分人无法戒掉的一个毛病。

分析：可以看见(B)选项在文章的前提和结论之间架了一个桥。这是假设题答案的一个重要特征，大家可以根据这个特点在读不懂文章的情况下做出正确答案。

例2、Even though most universities retain the royalties from faculty members’ inventions, the faculty members retain the royalties from books and articles they write. Therefore, faculty members should retain the royalties from the educational computer software they develop.

The conclusion above would be more reasonably drawn if which of the following were inserted into the argument as an additional premise?

(A) Royalties from inventions are higher than royalties from educational software programs.

(B) Faculty members are more likely to produce educational software programs than inventions.

(C) Inventions bring more prestige to universities that do books and articles.

(D) In the experience of most universities, educational software programs are more marketable that are books and articles.

(E) In terms of the criteria used to award royalties, educational software programs are more nearly comparable to books and articles than to inventions.

翻译：尽管大部分大学拥有了他们教员发明的版税，但是教员却拥有他们所写的书和论文的版税，因此教员应该拥有他们所开发的计算机软件的版税。

问：下面哪一项作为一个附加的前提被加上的话，上面的结论将会被推出?

(A) 发明的版税比教育软件的版税要高;

(B) 教员更有可能做出教育软件，而不是发明;

(C) 发明带给了出书和文章的大学更高的威望;

(D) 大部分大学的经验当中，教育软件比起书和论文更容易市场化;

(E) 根据过去给的版税标准，教育软件和书、论文的相似程度比起发明更大一些。

分析：这篇文章阅读起来是有困难的，关键是看不懂“书、论文”和“教育软件”之间的关系，但这正是我们要注意的，因为推导缺陷就在于此，假设的答案也就产生于此处。E 选项说明了教育软件和书、论文两者之间的关系，所以是正确答案。

2、非常理原则

对于常识的把握是我们和美国人最大的区别。美国人讲究“逻辑推理”(当然本身由于从小的教育，常识也就少一些)，我们讲究“常识推理”，而GMAT的题目是ETS按照美国人的思维方式来出的，我们应该注意减少常识，这样才能避免错误和迅速定位答案。我们来看一个例子。

例3、Samples from a ceramic vase found at a tomb in Sicily prove that the vase was manufactured in Greece. Since the occupant of the tomb died during the reign of a Sicilian ruler who lived 2,700 years ago, the location of the vase indicates that there was trade between Sicily and Greece 2,700 years ago.

Which of the following is an assumption on which the argument depends?

(A) Sicilian potters who lived during the reign of the ruler did not produce work of the same level of quality as did Greek potters.

(B) Sicilian clay that was used in the manufacture of pottery during the ruler’s reign bore little resemblance to Greek clay used to manufacture pottery at that time.

(C) At the time that the occupant of the tomb was alive, there were ships capable of transporting large quantities of manufactured goods between Sicily and Greece.

(D) The vase that was found at the Sicilian tomb was not placed there many generations later by descendants of the occupant of the tomb.

(E) The occupant of the tomb was not a member of the royal family to which the Sicilian ruler belonged.

翻译：在西西里的一个坟墓中发现的陶瓷花瓶的取样证明这个花瓶是在希腊生产的。因为坟墓的主人死于2700年前西西里某位君王的统治时期，所以这个花瓶的位置表明在2700年前西西里和希腊之间就已经有贸易了。

(A) 生活在那位君王统治时期的西西里陶工生产的产品质量和希腊的陶工不同。

(B) 在那位君王统治时期生产陶器所使用的西西里粘土和同时期的希腊粘土不太相似。