◆◇五中選二的原則（theruleof2outof5）
邏輯推理題編寫的一個基本原則是五個選項中的一個選項必須比其他的四個好。然而，正確選項的設計不能比其他四個選項明顯地好以致問題的難度變得太小。這個原則使邏輯推理的命題人員陷入了左右為難的境地。如果一個問題讓你去駁斥一個論證，那么一個選項必須能對段落的內在邏輯構成反對。這個選項將是“creditedresponse”。另外四個選項——迷惑選項distractors一定在某些方面不完美，但他們不能不一目了然，使問題變得ridiculouslyeasy。從某種意義上講，preparingworkabledistractorsisactuallymoredifficultthanwritingthecreditedresponse。因此，通常五個選項中只有兩個選項值得考慮（兩者中僅僅在一個是對的）。另外三個選項，儘管有時與推理主題有點關聯，但它們都有忽略了論點的推理結構。牢記：usuallyonlytwooftheanswerchoiceshaveanyrealmerit(onebeingthecorrectchoice).
總之，使得五個選項中只有一個難以排除，其他三個選項在很多情況下可能與問題目的無關，所以怎么樣迅速排除三個選項是提高解題速度的關鍵。我在與ets負責命題的官員談話時明顯覺察到：編制邏輯推理題的最大痛苦與挑戰不在於如何編制出一個非常像正確答案但又絕對不是正確答案的選項。實際上，有時五個選項中四個選項都編得極為荒謬，錯得極為明顯，只要閱讀水平沒問題，正確答案便躍然紙上。讀者應在本書的大量歸類講解與訓練中，培養挑選正確選項的感覺，進而找出錯誤選項特徵。請看下面這個例子：
overthepastfifteenyears,thelargelyurbanizednortheasternunitedstateshasshownmoreandmo
retheinfluenceofthesouthwesternportionofthecountry.once,veryfewpeopleinnewyorkcityc
ouldbefoundsportingcowboybootsandstetsonhats,andnomajorradiostationboastedtwenty-f
our-hour-a-dayprogrammingofcountryandwesternmusic.thelatestdevelopmentistherapidproliferationo
frestaurantsservingchili,nachos,burritos,andothertex-mexdishes.thepassageabovemakeswhichofthefollowingassumptions?
(a)thelifestyleofpeopleinthenortheasthasbeenenrichedbytheinfluenceofthesouthwesternstates.
(b)mostresidentsofthesouthwesternstatesregularlyeatattex-mexrestaurants.
(c)overthelastfifteenyears,residentsofthesouthwesternunitedstateshaveincreasinglyadoptedlife
stylessimilartothoseofthenortheast.
(d)tex-mexdishesareanelementoftheregionalcuisineofthesouthwesternstates.
(e)peopleinthenortheasternunitedstateseatoutmorefrequentlythantheydidfifteenyearsago.
解析：本題的正確答案是（d）。theauthorclaimsthatthenortheasthasabsorbedelementsofthecultureofthesouthwestandpro
videsthreeexamples.atacitassumption(onewhichisnotproved)oftheargumentisthatacertainmodeofdress,akindofmusic,andatypeofcuisinearefoundintheso
uthwest.(d)articulatesthisassumption.
threeoftheremainingchoicesarereallyjust“flak.”theylackany6realplausibilityafterareasonablycarefulreading.theseare(a),(c),and(e).
(a)goesbeyondthescopeoftheinitialstatement.theauthorsimplystatesthatcertainculturalelement
softhesouthwesthavebeentransplantedtothenortheast,butnovaluejudgmentiscontainedinthepa
ragraphaboutthatprocess.
(c)reversesthecausallinkagedescribedbytheinitialstatement.accordingtotheauthor,thesouthwest
hasinfluencedthenortheast---notviceversa.
(e)goesbeyondthescopeoftheinitialstatement.nothingintheargumentsuggeststhatpeopleintheno
rtheastareeatingoutmorefrequentlythantheydidfifteenyearsago----onlythattheremoretex-mexrestaurantsintheregionthantherewerefifteenyearsago.
對大多數人而言，（b）最易誤選。itatleasthasthemeritofbeingfairlycloselyconnectedtotheargumentintheinitialstatement.itmigh
tbetruethatpeopleinthesouthwestregularlypatronizethetex-mexrestaurants.that,however,isnotnecessarilyanassumptionoftheargument.allthatisrequired
fortheargumentisthatthereexistinthesouthwestsuchrestaurants---notthatresidentsofthatareapatronizethoserestaurantswithanyfrequency.
由上例可以看出，五個選項中的（a）、（c）和（e）的編寫都非常荒謬，錯得較為明顯。“五中選二”的兩個選項為（b）、（d），也就是說這五個選項中只有（b）、（d）值得考慮。（b）易誤選。而正確答案只有一個，即（d）。