Critical Reasoning [Compatibility Mode]

8/14/2019 Critical Reasoning [Compatibility Mode]

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Strategy for Critical Reasoning

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Aim



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Logic, not Grammar

Critical Reasoning problems are among thetrickiest question types youll come across in theGMAT.

Thats because CR problems are logic-based.

While an understanding of English grammarrules is essential, your major challenge will besimply to learn how ETS expects you toapproach the information within the sentences.

For many, this is the most feared part of the test!

Why do they fear it so?

Because the world as we know it is notlogical.



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By deconstructing a Critical Reasoning argument, you can moreclearly see what it is thats missing.

Deconstructing an argument helps you notice illogicalconnections. The tendency to make sense of what we read isnatural and, for the GMAT, fatal.

Fight your normal reading habits as you go through the questionsin this lesson.

With each CR question, youll be presented withan argument. Dont try to break down theargument into its essential parts.

Instead, reorder the information.

Reorder the information; identifying thepremises and conclusion inherent within eachargument.

For Critical Reasoning questions, you must be purely and consistentlylogical.



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You: Lets go see a movie.

Me: I have only two dollars.

Make sure youre not brining outside information into yourreading of a Critical Reasoning problem.

We pose arguments all the time.

Often there is no logical connection between the information wepresent (our premises) and our conclusions.

For example

What is your conclusion? We cant go to a movie.

Because a movie costs more than two dollars.But why?

But how do we know this? We dont!

Dontassume

informationunless yousee it in the

argument!



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Me: I cant believe I saw Joe drinking a Coke.

You: Why?

Me: Because Joe works for Pepsi.

Whats your conclusion?

Joe prefers Coca Cola.

Joe hates his job.

Joe is a spy for Pepsi.

Be careful! What kinds of assumptions are you making to reachthese conclusions?

Heres another example



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On Thursday I wore a blue shirt.

On Friday I had a headache.

Therefore, my blue shirt gives me a headache.

This is a dumbed-down version of a Critical Reasoning problem.Its easy to argue with my logic when I present my argument sosimply.

Be always suspicious of CR arguments. Fight with them. Whatcould yousay that would undermine myargument?

Perhaps I was out all night last Thursday.

Maybe I live next door to an airport.

Any of these statements could severely undermine, or weaken,my argument. And what could you add that would completelydestroyit?

What do you make of this one?



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Theres no connection between the headache and the shirt

On Thursday I wore a blue shirt.

On Friday I had a headache.

My health is affected by the clothes I wear.

Therefore, my blue shirt gives me a headache.

This piece of information would completelydestroymy argument.

And the reverse, that there is a direct connection between theheadache and the shirt, would completely fix it.

Now take a look at my revised argument

Youll never find an argument like this in a Critical Reasoningproblem. Its too logical!



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Your task as you approach CR questions will beto break down an illogical argument into itsstated premisesand conclusion.

If you can do this, youll be able to spot any trickthat ETS test-makers throw at you.

There are several different types of Critical Reasoning questions.Differentiating between them is difficult, and youll have to knowthe approach for each of them when you sit down to take the test.

Critical Reasoning questions ask you to do several things, but centralto them all is having an understanding of the basic structure of an

argument.



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Key Terms

Argument

Central to every CR question is the argument. An argument is anordered line of reasoning composed of premises, assumptions, anda conclusion. Understanding the elements of an argument isessential to performing well in this section.

Premise

Each CR argument contains at least one premise. Premises arepieces of information that provide evidence used to support theconclusion of the argument. For the purposes of Critical Reasoningarguments, premises are facts not subject to dispute.

Conclusion

The conclusion is the endpoint of the line of reasoning of anargument. Think of it as the result of the argument. The line ofreasoning leading to a conclusion is often where errors in logic aremade.



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Key Terms

Assumption

Assumptions are unstated facts and logical connections in anargument. In order for the conclusion of an argument to be true, theassumptions upon which that argument is based must also be true.



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The Approach



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Step 1: Read the question first.

Step 2: Read the argument.Step 3: Paraphrase the argument using your own words.

Step 4: Predict the answer.

Step 5: Use the process of Error Identification to eliminate thewrong answers.

The Approach

Critical Reasoning questions test your ability touse basic logic to analyze and critiquearguments made up of premises andconclusions. ETS test-makers write argumentsthat assume information which doesnt exist!

A logical and consistent approach is the bestway to avoid formulaic traps.

Follow these steps each time you attack CriticalReasoning questions.



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Its natural to read the question afterthe argument because thats howtheyre presented on the page. This is done for a reason.


Reading the argument first is confusing.

Read the question and determine what to look for within the answerchoices.

In general, youll be looking for the answer choices that eitherstrengthen or weaken the argument.

Think of answer choices as additional premises. Adding any oneanswer choice to the argument will do one of three things:

1. It will weakenthe argument.

2. It will strengthenthe argument.

2. It will not affect the argument at all (neutral).

3. It has nothing to do with the argument (out of scope).

Determine which of the eight kinds of Critical Reasoning questionsyoure facing before turning to the argument itself.



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Step 2: Read the argument.

1. Identify each premise (each piece of information) that is beingpresented within the argument.

2. Identify the arguments conclusion.

3. Determine what assumptions are being made.

Step 3: Paraphrase the argument using your own words.

Critical Reasoning arguments are intentionally heavy, wordy andcomplex. Paraphrasing is a good way of understanding the sense anargument presented.

Take the time, if necessary, and restate an argument, using words and

situations that you can relate to.Note: This is the only step youre permitted to skip. While itsnecessary to understand the meaning of each argument (andparaphrasing is a good tool to help you do this), restating orparaphrasing an argument brings you unavoidably further away fromthe actual text.



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So, youve read the argument. You understand it. You can identify itspremises and its conclusion. Now imagine additional premises(additional pieces of information) and what affect each would have onthe argument overall.

Brainstorm for a moment. Imagine which additional premise wouldbest strengthen the argument. What one thing could you add thatwould completely fix it? Now imagine the opposite. How could you

weaken the argument? How could you completely destroy it?

This is perhaps the most important step in the process. Answerchoices are intentionally misleading, and you can use your predictionsas a measuring stick with which to compare the choices given to youby ETS.



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Think of answer choices as additional premises. As you read eachchoice, ask yourself, How would this additional premise affect thestrength or weakness of the arguments conclusion?

Categorize answer choices as one of the following:

1. Strengthen

2. Weaken2. Neutral

3. Out of scope

Use the Process of Error Identification to get rid of any choices that donot affect the conclusion (neutral) or have nothing to do with theargument whatsoever (out of scope).

Whether you eliminate strengthenor weakenanswer choices dependson the question related with that argument.

Try the following Critical Reasoning example, using five steps

Step 5: Use the Process of Error Identification to eliminate thewrong answers.



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In years past, professional baseball players lifted weights less but

were also injured less often during games. Obviously, the more anathlete lifts weights, the higher the likelihood of injury.

The conclusion above presupposes which of the following?

(A) The increase in baseball injuries is due to a factor other thanweightlifting.

(B) The activities of baseball players represent those of athletes

as a group.(C) Most baseball injuries today result from too much weight-

lifting.(D) There is no proven correlation between how much athletes lift

weights and how likely they are to be affected by injury.(E) Weightlifting has always been common practice for

professional athletes.



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First, read the question.

The conclusion above presupposes which of the following?

Premise #1: In years past, professional baseball players liftedweights less.

Premise #2: But they were also injured less often during games.

Conclusion: Obviously, the more an athlete lifts weights, thehigher the likelihood of injury.

This is whats called an assumption question. What specific piece ofinformation is presupposed (assumed) in the preceding argument?

Break it down to understand what the writer is really saying.Can you identify the premises and the conclusion?

Restate or paraphrase the argument, if necessary. Stick as close tothe actual text as possible.

The correct answer is (B). Lets see how its done



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If necessary, paraphrase the argument. Put the events in a contextyou can understand, but stick as close to the actual text as possible.

Try changing the subjects without changing what they did.Keep trying until the GMAT argument makes sense to you. Thenreturn to the actual argument!

Now, think about some of the big assumptions that are being made.

Ask yourself what you could add to fix the argument.

What could you add to the argument to completely destroy it!

If it helps, imagine someone you cant stand. Think up a real orfictional know-it-all. Now come up with the one thing you could say tothis person that would shut him up.

What if I offered evidence that proved baseball injuries are

definitely not a result of weightlifting? That might destroy theargument. And the contrary, that baseball injuries definitely arearesult of weightlifting, might fix it.

What other assumptions can you come up with?



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When youre ready, turn your attention to the answer choices.

Use the Process of Error Identification to eliminate any answer choices

that are neutral or out of scope. For this particular question, alsoeliminate any answer choices that weaken the argument.

(A) The increase in baseball injuries is due to a factor otherthan weightlifting.

(B) The activities of baseball players represent those ofathletes as a group.

(C) Most baseball injuries today result from too muchweightlifting.

(D) There is no proven correlation between how muchathletes lift weights and how likely they are to beaffected by injury.

(E) Weightlifting has always been common practice forprofessional athletes.



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(A) The increase in baseball injuries is due to a factor otherthan weightlifting.

(B) The activities of baseball players represent those ofathletes as a group.

(C) Most baseball injuries today result from too muchweightlifting.

(D) There is no proven correlation between how muchathletes lift weights and how likely they are to beaffected by injury.

(E) Weightlifting has always been common practice forprofessional athletes.

Only answer choices (B) and (C) strengthen the argument.

Of course, there are many different kinds of athletes. All athletes are

not baseball players. The correct answer is (B).

Be aware of vague and undefined categories, such as athletes.

Whats wrong with answer choice (C) ? The trigger word most isundefined. Most is a relative term, but we dont know what itsrelative to.

Weakens

Weakens

Neutral



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In 1991, produce growers began using a new, inexpensivepesticide, provoking many objections that they would damageboth the environment and the produce they were growing.However, the fears have proven unfounded as, though 1996,produce prices had dropped and no ill effects had been reported.

Which of the following, if true, would be the strongest

objection to the argument above?(A) Consumption of the produce declined from 1991 to 1993, but

rose sharply from 1994 to 1996.(B) Several areas in which use of the pesticide was forbidden

have also experienced a drop in produce prices.(C) The amount of produce grown in 1991 was larger than that of

1996.

(D) The time since the beginning of the use of the pesticide hasbeen too short to allow some of the predicted effects to

occur.(E) Since 1992, new pesticides have been developed that

scientists agree are relatively risk-free.

Try one more



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(D) is the only answer choice that weakens the argument.

All the others, in fact, are out of scope!

Make it personal

In 1991, I started smoking cigarettes. Myfriends said it is unhealthy. In 2000, I am still

Okay: Therefore; cigarettes are not unhealthy.

Theres a fatal flaw to this logic. Look back and compare this

rephrasing with the actual argument itself.

Sorry, thecorrect

answer is(D).



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(D) is the only answer choice that weakens the argument.

All the others, in fact, are out of scope!

Make it personal

In 1991, I started smoking cigarettes. Myfriends said it is unhealthy. In 2000, I am still

Okay: Therefore; cigarettes are not unhealthy.

Theres a fatal flaw to this logic. Look back and compare this

rephrasing with the actual argument itself.

Good job!



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Good luck!

Practice, Practice, Practice!

The best way to prepare for Critical Reasoningquestions is to practice Critical Reasoningquestions.

Take your time as you go through the testquestions in the next section.

If have difficulties, dont worry. CriticalReasoning is the most dreaded question type inthe exam!



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Click on the Next Screenbutton to see a brief description of these eightCritical Reasoning question types.

Critical Reasoning Question Types

The GMAT is, if anything, predictable.

There is a limited variety of questions youll beasked relating to a Critical Reasoning argument.

There are, in fact, eight definitive types of CriticalReasoning questions. Each question type has

its own traps and a specific strategy is requiredto ace each one of them.



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Critical Reasoning Question Types

1. Draw a conclusion

2. Assumption

3. Strengthen

4. Weaken

5. Inference

6. Explain the (apparent) contradiction

7. Complete the passage

8. Except questions



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Fire!



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Click on the oval that corresponds with your choice.

A scientist planted two groups of plants under identical conditionsof light, temperature, humidity, and moisture. Every day he wouldplay sound effects of thunderstorms to one of the groups of plants

and sounds of city traffic for the other. The group to which heplayed thunderstorms all died within a few weeks, but the othergroup thrived during the experiment. He therefore concluded thatthe sound of city traffic is more effective for helping plants growthan is the sound of thunderstorms.

Which of the following, if true, would most seriously weakenthe scientists conclusion?

(A) The scientist put different varieties of plants in each group.(B) The light affecting the plants changed according to the time

ofday.

(C) The plants in the group for which he played city trafficsounds

died several weeks after the experiment.

(D) The plants were all purchased at the same time.(E) The plants in the group for which he played city traffic

soundsrequired more water than the scientist actually gave them.

Weigh eachchoice

carefullybefore

eliminating it.



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Youve got it! We know we have two groups of plants. Whatsassumed is that both groups are the same!

Try a harder one

In response to years of increasing congestion at airport X, thegovernment decided to redistribute landing slots. Henceforth, allinternational flights arriving from continent A would be rerouted tonearby airport Y, all flights arriving from continent B would continue to

land at airport X. Several airlines opposed this measure on thegrounds that it would result in lost business.

Which of the following, if true, justifies the airlines conclusion?

(A) The airlines customers prefer less congested airports.(B) It takes five minutes more flying time to reach the second

airport.

(C) There are fewer runways, and thus less capacity, at airport Y.(D) Airport Y is located in a region with better transport links to

thefinal destinations of many travelers from continent B.

(E) Many customers traveling between continent A and continentB choose certain airlines because of the easy flightconnections they offer at airport X.



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Sorry, the correct answer is (A). Lets look at this problem usingthe MBA Centers five steps.





Step 5: Use the process of Error Identification to eliminate

the wrong answers.

Which answer choice will bestweakenthe arguments

conclusion?

Imagine a piece of newinformation that woulddestroythe argument.

If necessary, translate it intosomething that makes sense.

Make it personal.

Identify the premises, theconclusion, and the flaw (the

assumption).

Eliminate any answer choices

that strengthen or are out ofscope.

Who said theplants in

both groupsare thesame?



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Heres an easier one

A citys public transportation board has decided to cut costs by reducingthe frequency of its bus service from an average of eight minutes to anaverage of ten minutes between buses. The board announced that itcan do so without seriously reducing the quality of service.

Which of the following statements, if true, would most strengthenthe validity of the boards announcement?

(A) The less frequent use of the buses will lower maintenancecosts, resulting in savings that can be used for much-neededrepairs of the citys pedestrian bridges.

(B) At rush hour, congestion in the city slows bus service by thirtypercent.

(C) Because of a robust economy in the city, passenger patronagehas increased substantially in recent years.

(D) The public transportation board has recently gathered data on

the levels of ridership on all bus lines, showing that some linesare used by many more riders than others.

(E) The contract with the bus drivers union stipulates that the citynot lay off any drivers because of reduced bus service.



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Right again!

This ones harder still

Kobayashi coffee has more caffeine than Marlowe Select coffee. Butsince Chula Vista coffee has more caffeine than Valentino coffee, itfollows that Kobayashi coffee has more caffeine than Valentino coffee.

Any of the following, if introduced into the argument as an

additional premise, makes the argument above logically correctEXCEPT?

(A) Marlowe Street coffee has more caffeine than Valentinocoffee.

(B) Marlowe Street corree has more caffeine than Chula Vistacoffee.

(C) Marlowe Street and Chula Vista coffees have the same

amount of caffeine.(D) Kobayashi and Chula Vista coffees have the same amount of

caffeine.(E) Chula Vista coffee has more caffeine than Kobayashi coffee.



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Sorry, the correct answer is (E). Lets look at this problem usingthe MBA Centers five steps.





Step 5: Use the process of Error Identification to eliminate

the wrong answers.

Which answer choice will bestweakenthe arguments

conclusion?

Imagine a piece of newinformation that woulddestroythe argument.

If necessary, translate it intosomething that makes sense.

Make it personal.

Identify the premises, theconclusion, and the flaw (the

assumption).

Eliminate any answer choices

that strengthen or are out ofscope.



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There you go!

It has often been hypothesized that global oil consumption, whichincreases every year, will deplete the supply of oil, with catastrophicresults for the global economy. However, these claims never stand upto scrutiny, as the volume of oil in reserves around the world hasremained constant.

Which one of the following, if true, best resolves the apparent

paradox?(A) The actual annual consumption of oil is below that which many

experts estimate.(B) The cost of operating oil refineries has steadily decreased

over time.(C) The consumption of oil has greatly increased in the past 50

years.

(D) It is the policy of all major oil producers to locate new reservesat a rate consistent with that at which old reserves aredepleted.

(E) The number of oil-producing countries has been steadilydeclining.



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Use the Process of Error Identification toeliminate answer choices (B), (C) and (E).Those weaken the argument.

Answer choice (D) is neutral. Some lines areused by many more riders than others. This tellsus nothing.

Click on the Previous Section button and try these questionsagain.

Sorry, the correct answer is (A).



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A popular Internet service provider changed its billing system, chargingcustomers per each connection to the system rather than per totalhours connected. According to company representatives, under thenew system, customers will spend more time connected to the Internetwhile being billed the same or smaller amounts.

Which one of the following statements, if true, would moststrengthen the conclusion of the company representatives?

(A) Customers will connect to the service less frequently andspend more time connected to the service each time they do.

(B) The change in the billing system will attract new customersresulting in increased profits for the company.

(C) By spending more time connected to the Internet customerswill be able to take advantage of services that previously would havebeen too expensive.

(D) The popularity of other Internet service providers relies on theirhaving billing systems similar to the one this company is adopting.

(E) The companys employees, all of whom have free unlimitedInternet access, support the change in billing.

Heres an easier one



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Right again! Wow, youre a Critical Reasoning wiz. You ought togo on television. This ones even more difficult

The owners of gambling casinos are keen to attract inexperiencedpoker players because, on average, these people lose money to thecasino, which increases the casinos profits. This is because theaverage inexperienced player does not have sufficient skill at the gameto win.

Which one of the following can be inferred from the aboveargument?

(A) There is always an element of chance when playing poker.(B) The probability of winning a game of poker increases with

experience.(C) Casinos make extremely large profits.

(D) Inexperienced players lose more money than they expect towhen playing poker at casinos.

(E) All games played at casinos involve an element of risk.



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Way to go! Try one more

Which of the following best completes the passage?

Critics of Country As trade policy with Country Z contend that CountryAs low tariffs are responsible for its large trade deficit with Country Z.Government officials, however, argue that there is a trade deficit withCountry Z because low labor costs in Country Z allow its companies to

manufacture goods cheaply. The officials also claim that economiccompetition from Country Z is responsible for better prices for CountryAs consumers. Therefore, they say, the most logical way to lower thetrade deficit without hurting Country As consumers is to _________.

(A) raise the tariffs on goods imported from Country Z(B) encourage businesses in Country A to reduce their labor costs(C) increase taxes on all goods not manufactured in Country A

(D) improve the products manufactured by Country As companiesand market them heavily in Country A

(E) subsidize all of Country As companies that manage tomaintain their prices at the level of the goods produced byCountry Z



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Critical Reasoning

Got you that time!

You did well, and you only had problems with thefinal difficult problem.



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Critical Reasoning

Good job! You got the second wrong, but theother two were right.



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(B) is the best answer.

I got you on that one. Well done, though.

Inference isonce logicalstep awayfrom the

conclusion.

Critical Reasoning

Be careful! This one is an Inferencequestion.

The best answer will paraphrase words andideas from the text and contain an inference justone step in logic away from the message of thetext.

Whats inferred in the argument that a playermust have skill to win!



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Critical Reasoning

Good job!

You got the first one wrong, but you pulled itback up with two and three.



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Critical Reasoning

Sorry. You got the second problem right, but theother two were wrong.



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Youre a Critical Reasoning genius!

Critical Reasoning

What can I say?



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Critical Reasoning

Sorry. You got the first question right, but youanswered the next two wrong.



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Critical Reasoning

Got you that time!

Well done, though.

You got four out of five right. Keep it up andyoull be on your way to Harvard!



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Summary



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Summary

Remember the five steps when

approaching CR problems.

Critical Reasoning [Compatibility Mode]

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