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GMAT邏輯推理錯誤解析

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下面是小編整理的GMAT邏輯推理錯誤解析,針對各種相關問題進行分析並且給出建議,提供給大家參考。

GMAT邏輯推理錯誤解析

評價題隱含條件The United States is not usually thought of as a nation of parakeet lovers. Yet in a census of parakeet owners in selected comparable countries, the United States ranked second, with eleven parakeet owners per hundred people. The conclusion can be drawn from this that people in the United States are more likely to own parakeets than are people in most other countries.

Knowledge of which of the following would be most useful in judging the accuracy of the conclusion?

(A) The number of parakeets in the United States.

(B) The number of parakeet owners in the United States

(C) The number of parakeet owners per hundred people in the country that ranked first in the census

(D) The number of parakeet owners in the United States compared to the numbers of owners of other pet birds in the United States

(E) The number of parakeet owners per hundred people in the countries not included in the census.

明確題意以後,我們首先需要明確那裡是本題的結論與前提,本題結論的前提為“美國每一百人中擁有長尾鸚鵡的人數在進行比較的國家中處於第二位,結論為:相比較而言,美國人更加喜歡飼養長尾鸚鵡。在由前提向結論的推理過程中,考生往往會忽略一點,即結論中的most other countries除包括“selected comparable countries”還應包括那些沒有進行比較的國家,因此我們在判斷結論是否正確以前,還必須知道那些沒有參與過此調查的國家的狀況是怎樣的。所以E為正確選項。

總結本題,我們可以發現學生往往由於沒有準確理解題意,導致了推理方向出現偏差,在推理推斷的過程中,不僅僅要求考生只是簡單的讀懂文章而已,更重要的是應能橫向與縱向對邏輯題所隱含的問題進行分析性思維,也只有通過不斷練習,發現問題並解決問題,我們才能找適合自己的解題思路。

  找不出因果 無因就無果

在假設題型裡,如果想要找出段落推理的一個必要條件,那麼我們首先就應明確,這個必要條件就是使得推理必然成立的一個假設,假設必為支援性假設。

例:

The population of peregrine falcons declined rapidly during the 1950’s and 1960’s and reached an all-time low in the early 1970’s. The decline was attributed by scientists to the widespread use of the pesticide DDT in rural areas

Which of the following, if true, gives the strongest support to the scientists’ claim?

(A) DDT was not generally in use in areas devoted to heavy industry

(B) In the time since the use of DDT was banned in 1972, the population of peregrine falcons has been steadily increasing

(C) Peregrine falcons, like other birds of prey, abandon eggs that have fallen out of the nest, even if the eggs remain intact

(D) Starlings, house sparrows, and blue jays-birds the peregrine falcon preys on were not adversely affected by DDT in their habitats

(E) Other birds of prey, such as the osprey, the bald eagle, and the brown pelican, are found in the same areas as is the peregrine falcon.

題幹是由果推因,遊隼數量下降由使用殺蟲劑(DDT)所致,我們不妨將“遊隼數量下降”視為B, 而將“使用DDT”視為A, 如果由B→A正確,那麼我們就可以得出沒有A就不會存在現在的B,因此我們就可以推斷兩種情況,DDT禁用前與DDT禁用後遊隼在數量上的比較,如果在 DDT禁用後,遊隼數量開始增加的話,那麼我們就會非常肯定的是確實是殺蟲劑的使用導致了遊隼數量的減少。這種型別的'題目出錯的主要原因有兩點:一:考生無法把握題幹要求,在段落內容之外進行推理;二:無法將題幹給出的原因視做唯一原因。

  建議:

考生應能在平時的不斷練習的過程中,學習找出論點和結論的能力,並依據兩者的關係進行判斷,只要弄清論點和結論也就相當於找出了答案。在實踐練習中,考生也應善於從題幹所描述的物件中找出核心關鍵詞語,一般來講,我們可以通過在選項中加入Not 來判斷推理成立的有效性並排除那些誤選項。找不出討論物件本質關係 GMAT邏輯推理中的假設題型作為一類常考題型有著非常重要的意義,往往在考試時,考生卻不知道應該如何有效找到可以使得整個推理成立的必要條件,或者考生往往出於使推理一定正確的心理,在各個選項中游走不定,最終導致考生無法清楚到底哪個選項才是“真正”的符合題幹要求的推理條件。其實我們在解題的過程中把握一個宗旨,也許我們就會發現其實假設題型並非我們想象的那樣難,這個宗旨就是:只需要找到一個能使得推理成立的條件或者說是必要條件,我們不需要去保證通過這個條件推理一定做到正確。下面就讓我們通過例項對考生在假設推理的過程中容易出現的錯誤進行解析。

無法找出題幹中討論物件之間的本質關係

例:A thorough search of Edgar Allan Poe’s correspondence has turned up not a single letter in which he mentions his reputed morphine addiction. On the basis of this evidence it is safe to say that Poe’s reputation for having been a morphine addict is undeserved and that reports of his supposed addiction are untrue.

Which of the following is assumed by the argument above?

(A) Reports claiming that Poe was addicted to morphine did not begin to circulate until after his death.

(B) None of the reports of Poe’s supposed morphine addiction can be traced to individuals who actually knew Poe.

(C) Poe’s income from writing would not have been sufficient to support a morphine addiction

(D) Poe would have been unable to carry on an extensive correspondence while under the influence of morphine

(E) Fear of the consequences would not have prevented Poe from indicating in his correspondence that he was addicted to morphine.

上述題幹中提到:一、研究發現Poe的信件中未提及他患有嗎啡癮;二、Poe沒有嗎啡癮

本題極力在讓考生從“對Poe的信件調查[證據]→Poe未患有嗎啡癮[結論]”找出兩者的內在聯絡,5個選項中也給出了不同的假設,那麼我們只需通過反推,來找出一種能夠使得推理成立的假設條件即可,但考生往往會拋開“信件調查”去思考其他使得上述結論正確的條件(假設),換句話說考生往往會認為除了對信件的調查這樣一個證據以外,還可以有其他證據能夠推出Poe未患有嗎啡癮。通常來講,當一個推理是從一個我們已知的,已經發生的事實推斷出一個結論的時候,我們需要記住的就是,其中的隱含假設多為這個結論的唯一原因,換句話說,在本題中要想對Poe的信件做出說明,那麼我們只能假定Poe不會因害怕後果而不在其信件中提及對嗎啡的嗜好,本題的正確假設選項為E.