图文完整版: http://ndxica.pixnet.net/blog/post/42601352 在这里使用 IR 的一个题目，来讨论一个 CR 的观念 - 样本客观: 建议先花 2 mins 做完题目: http://goo.gl/FkDCwP -------------------------------------------------------------------------------------------- In an experiment, researchers posed simple questions in geometry to children from varied backgrounds. One group consisted of 7-to-13-year-old children of the Mundurucu, an isolated indigenous group in the Amazon basin. The Mundurucu children, who had no formal training in geometry, answered the questions just as quickly and accurately as did French chidlren of the same ages who did have formal training in geometry. In contrast, 5-year-old North American children had much more trouble answering the questions. The researchers concluded that some basic geometric knowledge is innate, but this innate knowledge typically develops only after age 5. In the table, select the statement that would, if true, most strengthen the researchers' conclusion and most weaken it, respectively. Make only two selections, one in each column. (A) North American children 7 to 13 years old had much more trouble answering the questions than did the Mundurucu of the same ages (B) None of the 5-year-old North American children had ever studied any geometry. (C) Mundurucu children who were 5 years old had just as much trouble answering the questions as did the 5-year-old North American children. (D) The researchers posed the same questions to 5-year-old French and Mundurucu children as they posed to the 7-to-13-year-old children. (E) Most of the children studied answered one or more of the questions incorrectly. -------------------------------------------------------------------------------------------- 题目大意: 研究人员发现，在 Amazon 的一个原住民部落 Munduruc’u，7 - 13 岁的小 孩没受过几何的正式训练，回答问题和法国同年纪的小孩 (受过正式的几何训练) 一样快 。相反的， 5 岁的北美小孩无法很顺利的回答这些问题。研究专家得出结论，认为基本 的几何知识是天生的，但这样天生的知识通常在五岁之後才会开始发展。 而 two - part analysis 要在选项中分别回答两个问题 (简介在此: http://ndxica.pixnet.net/blog/post/40130233)， 一个问题选一个答案 (两个答案可重复选同一个选项)。 在此题要回答 "Most Strength" 和 "Most Weaken" (所以必然是不可能选择同一个答案)。 在此题，题目的论点有着明显的一个落差 - 样本不一致。 5 岁的北美小孩对几何问题有障碍 (受过正式几何训练) + 7 - 13 岁的 Munduruc’u 小孩可顺利回答几何问题 (没受过正式几何训练) -> 推得几何知识是天生，且在 5 岁之後开始发展。 看似很 ok，但其实样本并不一致 - 样本为北美小孩和 Munduruc’u 小孩， 虽然题目已经交代了样本的教育程度，但不同的样本可能还有其他客观条件有所不同。 答案 (A) North American children 7 to 13 years old had much more trouble answering the questions than did the Mundurucu of the same ages 我们把此答案放入同一个样本 (北美小孩) 来比较: 5 岁的北美小孩回答几何问题有障碍 (题目资讯)， 而 7 - 13 岁的北美小孩回答几何问题比起 7 - 13 岁 Munduruc’u 小孩来说有更多的障碍 (答案资讯)。 证明了北美小孩并没有如研究人员所说的， 随着年纪增长 (超过 5岁)，而发展出天生的几何知识。所以 Weaken 了此题目。 答案 (C) Mundurucu children who were 5 years old had just as much trouble answering the questions as did the 5-year-old North American children. 我们把此答案放入同一个样本 (Amazon 原住民) 来比较: 5 岁的 Munduruc’u 小孩回答问题比起 5 岁北美小孩来说， 回答几何问题有更多的障碍 (答案资讯)。 而 7 - 13 Munduruc’u 小孩回答几何问题没有太多障碍 (题目资讯)。 证明了Munduruc’u 小孩如研究人员所说的，随着年纪增长 (超过 13岁)， 而发展出天生的几何知识。所以 Strengthen了此题目。 当然，其他答案可能多少会影响题目， 但并没有此两个答案直接讨论样本一致性来的大， 在此为了强调重点，以讨论此两个正确答案为主。 Two-Part Analysis 的题目类型，必须同时选出两个答案， 而此题目出得相当漂亮，正好可以用样本一致性， 同时讨论一个题目的加分 (Strengthen) 和扣分 (Weaken)，在此分享给各位。 -- Donz 8月两周冲刺班: http://ndxica.pixnet.net/blog/post/41341972 Donz + Keewee 速成实力暑假班: http://ndxica.pixnet.net/blog/post/40937209 Donz GMAT FB: https://www.facebook.com/groups/DonzGMAT --

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