Critical Reasoning - How to Crack the Verbal Section - Cracking the GRE Premium (2015) 

Cracking the GRE Premium (2015)

Part II How to Crack the Verbal Section

Chapter 7 Critical Reasoning

While ETS considers Critical Reasoning questions to fall within the category of Reading questions, the questions are different enough to merit a separate discussion. Let’s jump in!

CRITICAL REASONING

Critical-reasoning questions are composed of short reading passages, typically just one paragraph long, followed by a series of questions about the author’s argument. You should expect to see anywhere from two to four critical-reasoning questions within your two GRE Verbal sections.

Here’s a sample critical-reasoning passage and question:

For more than fifty years, many evolutionary biologists posited that early fish such as Eusthenopteron developed limbs as a result of the need to drag themselves across short distances when their watery habitats dried up during periods of drought. However, new fossil evidence suggests that this hypothesis is incorrect. Fossilized remains of Acanthostega, a primitive fish, reveal that even though the animal had rudimentary limbs, it could not walk on land. Acanthostega lacked ankles, which means that its limbs couldn’t support its weight; furthermore, its ribs were too short to prevent the organism’s chest cavity from collapsing once the animal left water.

Which of the following would most strengthen the author’s argument?

    The fossilized remains of the Acanthostega are the earliest known evidence of early fish.

    The modern descendants of Acanthostega are not able to drag themselves across short distances on land.

    Biologists have found that some aquatic species can successfully drag themselves across land even though these species do not possess ankles.

    Any animal with a collapsed chest cavity is not able to survive long enough to travel even a short distance across land.

    Some evolutionary biologists believe that the new fossils are not from Acanthostega.

The answer to this
question, by the way, is
(D). Not sure why?
Keep reading.

What Exactly Is Critical Reasoning?

Critical reasoning is our term for a specific type of reading passage you’ll encounter on the GRE. At first glance, critical-reasoning passages resemble the short Reading Comprehension passages. However, what distinguishes critical reasoning from a regular reading passage is twofold:

1.    The structure of the passage

2.    The types of questions ETS will ask about it

We’ll show you how to identify critical-reasoning passages and the most effective way of tackling these questions as well.

BREAKING AN ARGUMENT DOWN

The key to doing well on critical-reasoning questions is understanding how ETS authors construct an argument. All arguments contain two major parts—the conclusion, or the main point of the argument, and the premise—the facts that the author gives in support of his or her conclusion. Identifying these two parts is crucial to your success on these questions. Let’s start our analysis of an author’s argument in a critical-reasoning passage by learning how to identify the conclusion.

Identifying the Conclusion

The conclusion is the most important part of the argument; quite simply, it is the reason the argument exists. The conclusion of an argument is generally a statement of opinion—it’s the author’s belief or prediction about a situation. Let’s look at the sample critical-reasoning passage again:

For more than fifty years, many evolutionary biologists posited that early fish such as Eusthenopteron developed limbs as a result of the need to drag themselves across short distances when their watery habitats dried up during periods of drought. However, new fossil evidence suggests that this hypothesis is incorrect. Fossilized remains of Acanthostega, a primitive fish, reveal that even though the animal had rudimentary limbs, it could not walk on land. Acanthostega lacked ankles, which means that its limbs couldn’t support its weight; furthermore, its ribs were too short to prevent the organism’s chest cavity from collapsing once the animal left water.

The conclusion is the
author’s main point.

You can identify the conclusion of the author’s argument by asking yourself this question: What opinion does this author hold? Now underline the sentence that you think is the conclusion of the argument above.

If you underlined “new fossil evidence suggests that this hypothesis is incorrect,” you hit the nail on the head.

There are other ways of identifying conclusions in arguments. For example, often you can identify the conclusion by certain key words. Specifically, keep an eye out for the following:

An argument’s conclusion is often signaled by these words:

therefore    thus    consequently    and so    in conclusion

You should also look for any words that indicate an opinion, such as the following:

suggest    believe    hope    indicate    argue    follow

In addition, a conclusion is often a belief about what should or might happen. Look for the following:

should    would    must    will

Remember: The
conclusion is often the
author’s opinion about
what might happen.

Practice: Identifying Conclusions

Underline the conclusions of the arguments in the following critical-reasoning passages. Answers can be found in Part V.

1 of 5

Despite the support of the president, it is unlikely that the new defense bill will pass. A bipartisan group of 15 senators has announced that it does not support the legislation.

2 of 5

The earliest known grass fossils date from approximately 55 million years ago. Dinosaurs most likely disappeared from the earth around 60 million years ago. Based on this evidence, as well as fossilized remains of dinosaur teeth that indicate the creatures were more suited to eating ferns and palms, scientists have concluded that grass was not a significant part of the dinosaur diet.

3 of 5

Automaker X has lost over 2 billion dollars this year due to rising costs, declining automobile sales, and new governmental regulations. Because of the company’s poor financial situation, it has asked its employees to pay more for health care and to accept a pay cut. However, the workers at automaker X are threatening to go on strike. If that happens, automaker X will have no choice but to file for bankruptcy.

4 of 5

The rise of obesity among citizens of country Y has been linked to a variety of health problems. In response to this situation, the country’s largest health organization has called for food manufacturers to help combat the problem. Since the leading members of the nation’s food industry have agreed to provide healthier alternatives, reduce sugar and fat content, and reduce advertisements for unhealthy foods, it is likely that country Y will experience a decrease in obesity-related health problems.

5 of 5

Recent advances in technology have led to a new wave of “smart” appliances, including refrigerators that note when food supplies are low and place an order at the grocery store, washing machines that automatically adjust the wash cycle and temperature based upon the clothes in the machine, and doorknobs that can identify the house owner and automatically open the door. A technology expert predicts that, due to these new innovations, machines will soon outnumber humans as the number-one users of the Internet.

Some critical-reasoning questions ask you to find the conclusion of the argument. Here’s an example:

Mutation breeding is a method of crop development that requires breeders to first find plants that randomly display the traits researchers are looking for, and then breed those plants with other plants displaying similar traits. In order to bring about the required mutations, researchers bombard plants with thermal neutrons, x-rays, and known carcinogenic chemicals in order to damage the plant’s DNA. Today, almost all varieties of wheat grown commercially are products of mutation breeding. Ironically, when scientists discovered how to splice desirable genes directly into the plants, thus avoiding the use of harmful chemicals and radiation, critics derided the new process as potentially dangerous despite the lack of any supporting evidence, resulting in boycotts and bans on genetically modified foods.

The argument as a whole is structured to lead to which of the following conclusions?

    Genetically modified food may have been unfairly stigmatized by its critics.

    Mutation breeding produces safer food than does genetic modification.

    Foods produced by genetic modification are healthier than foods produced by mutation breeding.

    Researchers should stop using mutation breeding in order to modify foods.

    Genetic modification of plants is more cost effective than mutation breeding of plants.

Here’s How to Crack It

The conclusion, as you’ll recall, is the author’s opinion or belief. As you read the argument, look for indicators of the author’s opinion. The first three sentences of the argument do not state opinions; the author is simply describing the method of mutation breeding. However, in the fourth sentence, the author uses the word ironically. This is an indicator of how the author feels. The author believes it is ironic that genetically modified foods are banned, despite “any supporting evidence” that they are dangerous, while foods created with mutation breeding, which use “harmful chemicals and radiation” account for “almost all varieties of wheat …”

Now we just need to find an answer choice that matches this opinion. Answer choice (A) looks pretty close, so let’s hang on to it. Choice (B) is the opposite of what the author argues; the argument implies that genetic modification is safer. Choice (C) is close, but the argument doesn’t really discuss which foods are “healthier,” just that one type is banned and the other type isn’t. Choice (D) also isn’t discussed. The author thinks it’s ironic that genetically modified foods are banned, but never states that mutation breeding should be stopped. Finally, choice (E) doesn’t work because the argument doesn’t express any opinion about cost effectiveness. Thus, choice (A) is the best answer.

Finding the Premise

After you identify the conclusion of an argument, your next task is to find the argument’s premise. The premise (or premises—there can be more than one) is the evidence that the author gives in support of the conclusion.

You can find the premise of an argument in two ways. First, look for statements of fact. Critical-reasoning passages are usually based on statistics, surveys, polls, or reports and all of these things are premises—in fact, these are the most common types of premises. Second, you can use a strategy we call the “Why?” Test. Once you’ve found the conclusion, ask yourself “Why” you should accept it; the answer or answers to that question will be the premise(s). Let’s look again at the passage from the beginning of the chapter:

For more than fifty years, many evolutionary biologists posited that early fish such as Eusthenopteron developed limbs as a result of the need to drag themselves across short distances when their watery habitats dried up during periods of drought. However, new fossil evidence suggests that this hypothesis is incorrect. Fossilized remains of Acanthostega, a primitive fish, reveal that even though the animal had rudimentary limbs, it could not walk on land. Acanthostega lacked ankles, which means that its limbs couldn’t support its weight; furthermore, its ribs were too short to prevent the organism’s chest cavity from collapsing once the animal left water.

Why should you believe
this conclusion?

What facts does the author give in support of the conclusion? In this argument, the author provides the following facts: (1) Acanthostega lacked ankles, and (2) the creature’s ribs were too short to prevent its chest cavity from collapsing. These facts are the premises of the argument.

Finally, just like conclusions, premises have certain indicator words.

An argument’s premise is often signaled by these words:

because    due to    since    based on

Is the statement a fact,
something that you could
verify or prove? Then it’s a
premise.

Practice: Finding the Premise

For each of the following arguments, identify the premise or premises that support the conclusion. Answers can be found in Part V.

1 of 5

Despite the support of the president, it is unlikely that the new defense bill will pass. A bipartisan group of 15 senators has announced that it does not support the legislation.

Conclusion: _______________________________

Why?

Premise: _______________________________

2 of 5

The earliest known grass fossils date from approximately 55 million years ago. Dinosaurs most likely disappeared from the earth around 60 million years ago. Based on this evidence, as well as fossilized remains of dinosaur teeth that indicate the creatures were more suited to eating ferns and palms, scientists have concluded that grass was not a significant part of the dinosaur diet.

Conclusion: _______________________________

Why?

Premise: _______________________________

3 of 5

Automaker X has lost over 2 billion dollars this year due to rising costs, declining automobile sales, and new governmental regulations. Because of the company’s poor financial situation, it has asked its employees to pay more for health care and to accept a pay cut. However, the workers at automaker X are threatening to go on strike. If that happens, automaker X will have no choice but to file for bankruptcy.

Conclusion: _______________________________

Why?

Premise: _______________________________

4 of 5

The rise of obesity among citizens of country Y has been linked to a variety of health problems. In response to this situation, the country’s largest health organization has called for food manufacturers to help combat the problem. Since the leading members of the nation’s food industry have agreed to provide healthier alternatives, reduce sugar and fat content, and reduce advertisements for unhealthy foods, it is likely that country Y will experience a decrease in obesity-related health problems.

Conclusion: _______________________________

Why?

Premise: _______________________________

5 of 5

Recent advances in technology have led to a new wave of “smart” appliances, including refrigerators that note when food supplies are low and place an order at the grocery store, washing machines that automatically adjust the wash cycle and temperature based upon the clothes in the machine, and doorknobs that can identify the house owner and automatically open the door. A technology expert predicts that, due to these new innovations, machines will soon outnumber humans as the number-one users of the Internet.

Conclusion: _______________________________

Why?

Premise: _______________________________

Okay. So you know how to identify the conclusion and premise(s) of an argument. Are you ready to try a critical-reasoning question? Here’s one way in which ETS will test your knowledge of the parts of an argument.

What’s the conclusion?
What’s the premise?

A common myth is that animals can sense an impending earthquake. And while most geophysicists dispute this assertion and claim that there is no way to predict an earthquake, a new hypothesis for predicting earthquakes is generating interest in the scientific community. This hypothesis is based on a well-known principle: Subjecting rocks to extreme pressures causes the rocks to produce electrical currents. Now, a leading physicist has proposed that this principle may help predict earthquakes. For example, an earthquake along the San Andreas Fault in California could produce hundreds of thousands of amperes (units of electrical current) that would disrupt the ionosphere surrounding the earth. By monitoring the ionosphere for electrical fluctuations, scientists may be able to predict earthquakes.

In the argument above, the two boldfaced statements play which of the following roles?

    The first statement expresses the conclusion of the argument while the second statement provides support for that conclusion.

    The first statement expresses the conclusion of the argument as a whole; the second statement provides a possible consequence of the conclusion.

    The first statement presents support for the conclusion of the argument as a whole; the second statement states the conclusion of the argument.

    The first statement expresses an intermediary conclusion of the argument while the second statement presents a possible objection to the intermediary conclusion.

    The first statement provides support for a conclusion that the argument opposes; the second statement expresses the conclusion that the argument as a whole opposes.

Here’s How to Crack It

The key to cracking this question is using the “Why?” test. Let’s try using the “Why?” test on the two boldfaced statements and see which one works best. If we make the first statement the conclusion, we’d end up with something like this:

Conclusion: Subjecting rocks to extreme pressures causes the rocks to produce electrical currents.

Why?

Premise: By monitoring the ionosphere for electrical fluctuations, scientists may be able to predict earthquakes.

Does that make sense? Nope, so let’s eliminate any answers that say that the first sentence is the argument’s conclusion. That allows us to eliminate choices (A), (B), and (D). Now let’s see what happens if we flip the statements around:

Conclusion: By monitoring the ionosphere for electrical fluctuations, scientists may be able to predict earthquakes.

Why?

Premise: Subjecting rocks to extreme pressures causes the rocks to produce electrical currents.

That makes much more sense. Answer choice (E) states that the argument opposes the conclusion, which it doesn’t, so we can eliminate that choice. Answer choice (C) is the best answer.

The “Why?” test helps to identify premises and conclusions.

Locating Assumptions

Although ETS frequently asks critical-reasoning questions about the premise or the conclusion of an argument, there are a number of other question types that require you to work with one final part of an argument. The final part of an argument is the assumption. The assumption is never explicitly stated in the passage, which means that it can sometimes be tricky to find. Basically, the assumption is the missing link that connects the conclusion of an argument to its premise.

Let’s look back at one of the arguments you’ve already worked on.

Conclusion: It is unlikely that the new defense bill will pass.

Why?

Premise: A bipartisan group of 15 senators has announced that it does not support the legislation.

In order for this argument to be convincing, the reader has to make an assumption that because 15 senators do not support the bill, the bill will probably not pass. If you don’t assume that the opposition of 15 senators means that the bill is unlikely to pass, the argument fails. Thus, assumptions are necessary to a successful argument.

To find the assumption or assumptions in an argument, you need to look for a “gap” in the reasoning of the argument. You can often accomplish this by asking yourself the following question:

Just because (premise) is true, does it really mean (conclusion) is true?

For example, let’s return to another of the arguments you’ve already tackled.

Conclusion: Country Y will experience a decrease in obesity-related health problems.

Why?

Premise: The leading members of the nation’s food industry have agreed to provide healthier alternatives, reduce sugar and fat content, and reduce advertisements for unhealthy foods.

Now, let’s ask ourselves the question: Just because it’s true that the food industry has agreed to provide healthier alternatives, reduce sugar and fat content, and reduce advertisements for unhealthy foods, does it really mean that obesity-related health problems will decrease?

If you accept this argument, you must assume that the food industry’s actions will lead to a decrease in obesity-related health problems. That’s the missing link—or the assumption—required by the argument.

Practice: Locating Assumptions

For each of the following critical-reasoning questions, identify the conclusion and the premise. Then note what assumption is required to make the argument work. Answers can be found in Part V.

1 of 4

City University recently announced the retirement of Professor Jones. Professor Jones is a leading biologist and widely published author and her presence was a major factor in many students’ decisions to attend City University. The University predicts no decline in enrollment, however, because it plans to hire two highly credentialed biology professors to replace Professor Jones.

Conclusion: ____________________

Premise: ____________________

Assumption: ____________________

2 of 4

It is unjust to charge customers under the age of 25 more to rent a car than those over the age of 25. After all, most states allow people as young as 16 to have a driver’s license and all states allow 18-year-olds the right to vote.

Conclusion: ____________________

Premise: ____________________

Assumption: ____________________

3 of 4

It is easy to demonstrate that extraterrestrial life exists by simply looking at our own solar system. In our solar system, there are eight planets and at least one of them obviously has life on it. Thus, roughly 12.5% of planets in the universe should have life on them.

Conclusion: ____________________

Premise: ____________________

Assumption: ____________________

4 of 4

State A is facing a serious budget shortfall for the upcoming year. Recent polls indicate that 58% of voters in Township B approve of a proposed 2-cent gasoline tax in order to make up the deficit. It is clear, therefore, that the leaders of State A should institute the gas tax.

Conclusion: ____________________

Premise: ____________________

Assumption: ____________________

CRITICAL REASONING QUESTION TYPES

Now that you’ve familiarized yourself with the basics of an argument, let’s look at the types of argument questions you’ll encounter on the GRE. Each of the following types of questions will require you to first identify the argument’s premise and conclusion; after that, your task will vary depending on the type.

Reasoning Questions

You can identify Reasoning questions because they will have the following question stems:

In the argument given, the boldfaced statements play which of the following roles?

Which of the following best describes the function of the boldfaced statements in the argument above?

The argument above is structured to lead to which of the following conclusions?


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For Reasoning questions, you must isolate the premise and conclusion, but you don’t need to find the assumption.

Assumption Questions

Assumption questions are usually phrased in the following ways:

The argument above assumes which of the following?

The argument above relies on which of the following?

The author’s argument presupposes which of the following?

On assumption questions, you need to first locate the premise and conclusion. After that, look for the gap as described in the “Locating Assumptions” section above.

Strengthen Questions

Strengthen questions will ask you to make the argument stronger. You’ll be asked to do this by identifying answer choices that will support the assumption. Strengthen questions are often phrased as follows:

Which one of the following, if true, would most strengthen the argument?

Which of the following, if true, would most support the author’s argument?

Supporters of the argument would most likely cite which of following pieces of additional evidence?

To strengthen an argument, find the premise, the conclusion, and the assumption. The correct answer will be a premise that supports the assumption.

Weaken Questions

As we’ve learned, the assumption is what makes an argument work. It follows, then, that if you attack the assumption, you will weaken the argument. You can identify Weaken questions by looking for the following:

Which one of the following, if true, would most weaken the argument?

Which one of the following, if true, casts the most doubt on the argument above?

Which one of the following, if true, would most undermine the author’s argument?

On Weaken questions, once again you’ll need to find the premise, conclusion, and assumption. The right answer will attack the assumption, breaking the link between the premise and the conclusion.

CRACKING CRITICAL-REASONING QUESTIONS

Ready to tackle some critical-reasoning questions? Let’s go through steps you take when you run into one of these questions on the test.

The Basic Approach

When you identify a question as being a critical-reasoning question on the exam, go through the following steps:

1.    Read the Question Carefully. Don’t dive into the passage without being aware of exactly what you’re dealing with—start by making sure that it really is critical reasoning and not a plain old reading comprehension passage.

2.    Analyze the Argument. Identify the premise, conclusion, and assumption of the argument.

3.    Know What the Answer Needs to Do. For each type of question, you can know what characteristic the right answer needs. For example, a weaken question attacks the assumption of the argument.

4.    Use Process of Elimination. Process of Elimination (POE) is a valuable tool. If you’re not sure what the correct answer is, look for the wrong answers instead; eliminate them, and even if you still can’t identify the correct answer, you have a much greater chance of guessing the correct answer.

Try going through these steps on the following question.

After examining the bodies of a dozen beached whales and finding evidence of bleeding around the animals’ eyes and brains as well as lesions on their kidneys and livers, environmental groups fear that the Navy’s use of sonar is causing serious harm to marine animals. A leading marine biologist reports that sonar induces whales to panic and surface too quickly, which causes nitrogen bubbles to form in their blood.

The argument above relies on which of the following assumptions?

    Marine biologists have documented that other marine animals, including dolphins and sea turtles, have exhibited kidney and liver lesions.

    No studies have been conducted on the possible detrimental effects of sonar on marine animals.

    Whales in captivity panic only when exposed to man-made, rather than natural, sound waves.

    The presence of nitrogen bubbles in the blood has been demonstrated to cause damage to various internal organs.

    It is unlikely that the symptoms found in the beached whales could be caused by any known disease.

What type of
question is this?

Here’s How to Crack It

Let’s apply the four-step basic approach:

1.    Read the Question Carefully. This is an Assumption question—we know this because it asks you to determine what the argument relies on.

2.    Analyze the Argument. Be sure to precisely identify the conclusion and premise. You should come up with the following:
Conclusion: The Navy’s use of sonar is causing serious harm to marine animals.
Why?
Premise: Surfacing too quickly causes nitrogen bubbles to form in the whale’s blood.
Next, we need to locate the assumption. Remember to use the question we introduced earlier—here it would be phrased as follows:
“Just because the whales have nitrogen bubbles in their blood, does that really mean that sonar is causing them serious harm?”

3.    Know What the Answer Needs to Do. Assumptions connect the premise to the conclusion. So, you want an answer that has something from both the premise and the conclusion in it.

4.    Use Process of Elimination. Check out the grey box for some POE tips on “assumption” questions.

Eliminate answers that
aren’t relevant to the
argument!

Now, returning to the answer choices, let’s see which one is best. Answer choice (A) is wrong; this choice doesn’t connect the premise to the conclusion. Even though it states that other animals have exhibited similar symptoms, we need the answer choice to connect the symptoms—in whales—to the use of sonar. Choice (B) is wrong as well. (B) brings in information that isn’t part of the original argument: It’s irrelevant whether or not the Navy has conducted studies on the harmful effects of sonar. Answer choice (C) doesn’t help much either; the argument is not concerned with the situations under which whales panic. Answer (D) looks pretty good. It connects the nitrogen bubbles found in the premise to the serious harm mentioned in the conclusion, so hold on to this choice. Remember that you always need to check all five answers; however, answer choice (E) is no good. Like choice (B), this choice brings in information that isn’t relevant to the argument. The fact that the symptoms are unlikely to be caused by any known disease does not make the link between the sonar and the harm to the animals. Thus, choice (D) is the best answer.

POE for Assumption Questions

When you’re using POE on Assumption questions, always eliminate answer choices that do the following:

1.    Give New Information. The assumption must link the premise and the conclusion. Any answer choices that discuss information that is not part of the original argument are wrong.

2.    Have the Wrong Tone. The tone of the answer choice should match the tone of the argument. Arguments that have very strong conclusions require very strongly worded answer choices, and arguments that have milder tones require milder answer choices.

3.    Weaken the Argument. The assumption is necessary to the argument. Eliminate any answer choice that would weaken or hurt the argument—unless of course you’re dealing with a Weaken question!

Strengthen Questions

Here’s another critical-reasoning question:

The Japan Aerospace Exploration Agency has announced plans for a new unmanned space probe. The probe, named Hayabusa, will rendezvous with an asteroid some 290 million kilometers away from Earth and attempt to land on the asteroid. After the landing, Hayabusa will release a robotic rover which will photograph the surface of the asteroid and also collect rock and dust samples. The probe will then return to Earth with the samples. Scientists believe that the mission, if successful, will provide important clues about the composition of the early solar system.

Which of the following, if true, most strongly supports the scientists’ conclusion about the Hayabusa mission?

    Once the Hayabusa probe reaches the asteroid, researchers calculate that it will have a 60% chance of successfully landing on the asteroid.

    The asteroid targeted by the Hayabusa mission is known to have been formed at the inception of the solar system.

    The Japan Aerospace Exploration Agency has yet to experience a mechanical failure with one of its unmanned space probes.

    Some astronomers believe that many asteroids originate outside the solar system and are captured by the gravitational pull of the sun and planets.

    The Hayabusa probe is the first ever to attempt a landing on an asteroid.

Remember to identify the
question type first.

Here’s How to Crack It

Let’s again apply the four steps:

1.    Read the Question Carefully. It’s a Strengthen question; we know this because the word “strengthen” is actually used in the question!

2.    Analyze the Argument. Find the premise, conclusion, and assumption.
Here’s what you should end up with:
Conclusion: The mission, if successful, will provide important clues about the composition of the early solar system.
Why?
Premise: Hayabusa will release a robotic rover which will photograph the surface of the asteroid and also collect rock and dust samples.
Assumption: Rock and dust samples from an asteroid will provide scientists with information about the early solar system.

3.    Know What the Answer Needs to Do. To strengthen an argument, look for an answer that provides evidence that the assumption of the argument is valid.

4.    Use Process of Elimination. Check out the grey box on this page for some POE guidelines on Strengthen questions.

Always check all five
answer choices.

Looking back at the answer choices, we see that answer choice (A) is not the best answer. This answer is only half good, indicating that the probe has a better-than-even chance of landing successfully. However, it doesn’t address whether the probe’s mission will help scientists understand the early solar system. Eliminate this choice. Choice (B) seems to be right on the money. The answer we’re looking for should support the assumption that rock and dust samples from an asteroid will provide clues about the early solar system. Choice (B) states that the asteroid in question is, in fact, from the early solar system. Keep looking through—remember that you’re looking for the best choice.

POE for Strengthen Questions

When you’re using POE on Strengthen questions, always eliminate answer choices that

1.    Are Only Half Good. Some answers will be on the right track, but they won’t strengthen the argument enough. Again remember that you’re looking for the best answer, not an answer that might be good enough. You shouldn’t have to make any assumptions about the answer choice in order for it to strengthen the argument.

2.    Weaken the Argument. Typically, one of the answer choices will weaken the argument. Unless your task is to weaken the argument, you can easily eliminate it.

3.    Do Nothing. Some answer choices do nothing to the argument; they neither strengthen nor weaken it. Get rid of these; they’re decoys.

On Strengthen questions, note that answer choices that offer new information are okay, provided of course that they help strengthen the argument. Also note that answers that have strong tones are often correct for Strengthen questions.

Like answer choice (A), choice (C) is half right. However, while it might be helpful to know that it’s unlikely that the probe will suffer a mechanical failure, you still have to assume that the mission itself will aid scientists in their attempts to understand the early solar system. That’s just too much of a leap. Answer choice (D) actually weakens the argument. If asteroids come from outside the solar system, studying dust from them probably won’t help researchers understand much from the solar system. Finally, choice (E) does nothing for the argument. The fact that the probe is the first of its kind says nothing about its scientific value. It looks like choice (B) is best; choose it and move on.

Weaken Questions

Try one last critical-reasoning question:

Psychologists have just completed an extensive study of recently divorced parents in order to determine which factors contributed most to the dissolution of the marriage. The researchers found that in a great majority of the cases of failed marriages, the couples ate, on average, fewer than 10 meals per week with each other. From this data, the psychologists have determined that a failure to spend time together during meal times is a major factor leading to divorce.

Which of the following, if true, would cast the most doubt on the researchers’ hypothesis?

    Many couples who have long and successful marriages eat together fewer than ten times per week.

    Most of the couples in the study who were unable to share meals with each other worked outside of the home.

    People who lack a regular dining schedule tend to have more disorders and illnesses of the digestive system.

    Couples in the study who reported that they ate together more than ten times per week also indicated that they tended to perceive their relationships with their spouses as healthy.

    In many cases, people in unhappy marriages tend to express their displeasure by avoiding contact with their partners when possible.

Do you recognize what
type of argument this is?

Here’s How to Crack It

This is a Weaken question. Once again, we’ll break the argument down into its premise, conclusion, and assumption:

Conclusion: A failure to spend time together during meal times is a major factor leading to divorce.

Why?

Premise: In a great majority of the cases of failed marriages, the couples ate, on average, fewer than 10 meals per week with each other.

Assumption: A lack of time spent eating meals together causes marital problems; there is no other cause.

The assumptions are, first, that there is no other cause, and second, that the cause and effect are not reversed. Since we want to weaken this argument, we want to find an answer that attacks one of these assumptions.

Check out the grey box for POE guidelines on Weaken questions.

POE for Weaken Questions

The guidelines for Weaken questions are basically the same as those for Strengthen questions. Eliminate any answer choices that

1.    Are Half Good. Make sure the answer attacks the assumption thoroughly.

2.    Strengthen the Argument. Once again, one answer usually does the opposite of the question task—eliminate the odd man out.

3.    Do Nothing. Some answer choices neither strengthen nor weaken the argument: Eliminate them.

As is the case with Strengthen questions, new information and extreme tones in Weaken questions need not be eliminated.

Looking through the answer choices, you can probably see right away that answer choice (A) is not the correct answer. The argument is not about what successful couples do; it is only concerned with divorced couples. Move on. Choice (B) doesn’t really do anything to the argument; it’s unclear how this information would affect the causal link assumed in the argument. The same goes for choice (C): All this choice indicates is that there may be other problems linked to eating—it doesn’t address the connection between dining and marriage success.

Choice (D) seems like it might strengthen the argument. These couples are reporting a link between eating together more and perceiving their marriages as healthy. Eliminate this choice. Choice (E) is the best answer. This answer choice shows that the researchers have reversed the cause and effect. It is not that a failure to dine together causes marital strife; rather, couples that are already unhappy express it by not eating together. This weakens the argument, and (E) is correct.

OTHER CRITICAL-REASONING QUESTION TYPES

The GRE also contains inference and resolve/explain questions, which require you to use different approaches from those you use for Weaken and Strengthen questions. Let’s go through how to crack inference and resolve/explain questions now.

Inference and resolve/explain questions do not require you to find the premise and conclusion.

Inference Questions

An inference is a conclusion that’s based on a set of given facts. You can identify inference questions because they’ll look a lot like the following:

If the statements above are true, which of the following must also be true?

Which of the following statements can be properly inferred from the information above?

Based on the information above, which of the following can logically be concluded?

Here’s an example:

The Mayville Fire Department always fills its employment vacancies “in-house”—when a firefighter retires or leaves the force, his or her position is filled by interviewing all qualified members of the Mayville Department who are interested in the position. Only if this process fails to produce a qualified candidate does the department begin interviewing potential employees from outside the department. This year, the Mayville Fire Department has hired three new firefighters from outside the department.

If the statements above are true, which of the following must also be true?

    For the coming year, the Mayville Fire Department will be understaffed unless it hires three additional firefighters.

    Firefighters hired from outside the Mayville Fire Department take longer to properly train for the job.

    At the time of the vacancies in the Mayville Fire Department, either there were no qualified in-house candidates or no qualified in-house candidates were interested in the open positions.

    The three firefighters who left the department had jobs for which no other members of the Mayville Fire Department were qualified to fill.

    The three new firefighters are the first new employees hired by the Mayville Fire Department.

On inference questions,
you don’t have to find the
premise and conclusion.

Here’s How to Crack It

Inference questions are often associated with critical-reasoning passages that are not structured like the clear-cut arguments we’ve seen thus far. Often these wacky arguments don’t even have conclusions and premises; instead, they might simply resemble a set of facts.

Our strategy for approaching these types of questions, of course, begins with identifying them as inference questions. However, for Step 2, don’t attempt to identify a conclusion or premise; simply read the argument. If the argument is complex or hard to follow, don’t spend too much time trying to untangle it. Most of the work on inference questions should be done when you get to the answer choices.

For inference questions, Step 3 is simple. You’re just looking for an answer that is true based on the facts provided in the argument.

Check out the POE guidelines for inference questions in the grey box on the next page.

Let’s start with answer choice (A). This choice says that the department will be “understaffed.” Is there any part of the argument that indicates that this is true? Nope, so eliminate this choice. Answer choice (B) states that firefighters from outside the department take longer to train, but the argument says nothing at all about training. Eliminate this choice. Choice (C) states that either there were no qualified candidates in house or there were no qualified candidates interested in the jobs. Returning to the argument, we see that the hiring policy is that a vacant “position is filled by interviewing all qualified members of the Mayville Department who are interested in the position.” If this process fails, the department goes outside the department for candidates. Thus, since Mayville hired three new fire fighters from outside the department, answer choice (C) must be true.

Can you prove your answer
choice? If not, eliminate it.

POE for Inference Questions

On inference questions, eliminate answer choices that

1.    Go beyond the Information. Stick to the facts on inference questions. Avoid answers that are overly broad or general.

2.    Could Be True. The correct answer on an inference must be true. Answers that might be true or could be true are no good.

3.    Use Extreme Language. Be suspicious of strong language. The presence of words such as all, none, always, never, or impossible often means that an answer choice is wrong.

The key to inference questions is using Process of Elimination: Take each answer choice and return to the argument to see if you can prove that it’s true. If you can’t point to the part of the argument that supports the answer choice, the answer is wrong.

Let’s go through the remaining answers. Choice (D) is tempting, but on inference questions, we need to make sure that every part of the answer choice holds up to scrutiny. This answer states that no other members of the department were qualified to take the open positions. This could be true; however, based on the facts presented, it could also be true that there were qualified members who simply weren’t interested in applying for the position. Thus, choice (D) isn’t the best choice—it isn’t better than (C). Finally, choice (E) goes beyond the information presented. There is no way of knowing whether these new firefighters were the first new employees. Answer choice (C) is still the best.

Resolve/Explain

Some critical-reasoning questions will present you with a paradox—a set of facts that seem to contradict each other. On these questions, your task is to find the answer choice that best explains the contradiction. You can recognize these questions because they often contain the following phrases:

Which of the following choices would best explain the situation presented above?

Which of the following, if true, would best resolve the discrepancy above?

Which of the following, if true, best reconciles the seeming paradox above?

Take a look at the following example:

Over the past 10 years, the emergence of digital file sharing technology has threatened the traditional market for compact discs. Internet users are now able to share songs from their favorite artists with little or no loss of quality in the music, acquiring the songs they desire without having to purchase the entire compact disc. Music industry leaders contend that this practice violates their copyright and causes untold financial losses. However, consumer groups report that there has been an increase in the sales of compact discs.

Which of the following, if true, would best explain the situation above?

    Some consumers who have downloaded songs from the Internet have been sued by major record companies.

    Research indicates that persons who engage in file sharing or song downloading are usually only casual music fans.

    The music industry is developing new technology to help prevent users from downloading songs.

    Music artists tend to release more material, on average, today than they did 10 years ago.

    Compact discs released now often include bonus features that are appealing to fans, such as interviews with the band and music videos, that are not available for download.

Here’s How to Crack It

Like inference questions, resolve/explain questions require a slightly different approach. Step 1 remains the same—read the question and identify the question type. Once you’ve identified the question as a resolve/explain question, read the critical-reasoning passage. However, instead of looking for a premise and conclusion, for Step 2 you’re going to look for two facts that are in conflict. The basic pattern for a resolve/explain argument is as follows:

Fact I:
But
Fact II:

For the argument in the example, two facts are in conflict:

Fact I: Internet users are able to download individual songs instead of purchasing compact discs.

But
Fact II: There has been an increase in compact disc sales.

For resolve/explain questions, the correct answer shows how both facts can be true at the same time. Proceed to Step 4, use POE, and as you read each answer choice, ask yourself the following question:

How can both (Fact I) and (Fact II) be true?

Check out the POE guidelines for resolve/explain questions in the grey box.

POE for Resolve/Explain Questions

On resolve/explain questions, you should eliminate answer choices that

1.    Do Nothing. Many wrong answers simply do nothing to the paradox.

2.    Are Only Half Right. Some answers will deal with only half of the conflict. Make sure the answer you select addresses both facts.

3.    Worsen the Situation. Eliminate choices that appear to make the situation worse.

Let’s use Process of Elimination on the answer choices in our example. The first answer choice doesn’t resolve the conflict. It might explain why fewer users download music, but it doesn’t explain why compact disc sales have increased. Eliminate choice (A). Answer choice (B) does nothing to the paradox. The fact that the people who download music are casual fans doesn’t really explain anything. Like answer choice (A), choice (C) is partly correct; however, it doesn’t explain the increase in sales. Also, the answer choice states that the industry is “developing” technology; it doesn’t state that the technology has been implemented yet. So this couldn’t affect the current situation. Choice (D) doesn’t help much either. You might assume that more material on the market means that sales could increase even with downloading, but that line of thought requires you to fill in too many missing pieces. The correct answer should do all the work. Look at answer choice (E). This choice states that compact discs feature bonus material that can’t be downloaded. This could explain both the fact that people are downloading music and that compact disc sales are increasing. Since choice (E) is a more complete explanation, it’s the best answer.

WON’T ALL THIS TAKE TOO MUCH TIME?

While it may seem at first like you will need a lot of time to break down the arguments and apply the strategies, you’ll get faster at doing this with practice. It’s better to take your time and truly understand how the questions work than to rush through the problems, only to get them wrong.

Working more slowly
increases your accuracy,
which increases your
GRE score!

Critical Reasoning Practice Set

In this practice set, follow the steps exactly as we have presented them. Answers can be found in Part V.

1 of 5

In 1989 corporate tax rates in some regions of the United States fell to their lowest level in 15 years, while the rates in other regions reached new highs. In 1974 similar conditions led to a large flight of companies from regions with unfavorable corporate tax policies to regions with favorable policies. There was, however, considerably less corporate flight in 1989.

Which of the following, if true about 1989, most plausibly accounts for the finding that there was less corporate flight in 1989 ?

    The regions with the most favorable corporate tax policies had many of the same types of corporations as did those with unfavorable tax policies, but this was not true in 1974.

    In contrast to 1974, office rental costs in the regions with the most favorable corporate tax policies were significantly higher than rental costs in other areas of the country.

    In contrast to 1974, in 1989, the areas with the most favorable corporate tax policies reaped the most benefit from tax incentives, although the tax codes were particularly difficult to decipher.

    Tax incentives offered by foreign countries were higher in 1989 than in 1974.

    Individual tax incentives in the areas with favorable corporate tax policies were slightly lower than they were 15 years earlier in areas with favorable corporate tax policies.

2 of 5

Aramayo: Our federal government seems to function most efficiently when decision-making responsibilities are handled by only a few individuals. Therefore, our government should consolidate its leadership and move away from a decentralized representative democracy.

Tello: But moving our government in this direction could violate our constitutional mission to provide government of, for, and by the people.

Which of the following statements describes Tello’s response to Aramayo?

    Tello contradicts the reasoning used by Aramayo.

    Tello uncovers an assumption used in Aramayo’s reasoning.

    Tello brings up a possible negative consequence of accepting Aramayo’s argument.

    Tello reveals the circular reasoning used by Aramayo.

    Tello shows that Aramayo overgeneralizes a very special situation.

3 of 5

Business computer systems are designed to make workers more productive by automating a portion of the work that must be completed in a business process. As a result, the employee is free to perform more tasks that require human attention. Although productivity may be lost during a learning period, many businesses experience dramatic gains in productivity after installing a new computer system. While discussing the connection between productivity gains and computer systems, a well-respected business journal recently stated that the person who serves as the Chief Information Officer is the consummate business computer system.

By comparing a Chief Information Officer to business computer systems, the journal implicitly argues that

    Chief Information Officers should always communicate the value of computer systems to their companies

    the productivity of a company can be increased through the hiring of a Chief Information Officer

    many companies have not improved their productivity with new computer systems

    Chief Information Officers are more effective than are new computer systems

    the impact of a Chief Information Officer on a company’s productivity is difficult to measure

4 of 5

Whenever Joe does his laundry at the Main Street Laundromat, the loads turn out cleaner than they do when he does his laundry at the Elm Street Laundromat. Laundry done at the Main Street Laundromat is cleaner because the machines at the Main Street Laundromat use more water per load than do those at the Elm Street Laundromat.

Which of the following statements, if true, helps support the conclusion above?

    The clothes washed at the Elm Street Laundromat were, overall, less clean than those washed at the Main Street Laundromat.

    Joe uses the same detergent at both laundromats.

    The machines at the Oak Street Laundromat use twice as much water as do those at the Main Street Laundromat.

    Joe does three times as much laundry at the Main Street Laundromat as he does at the Elm Street Laundromat.

    Joe tends to do his dirtier laundry at the Elm Street Laundromat.

5 of 5

According to the United States Postal Service bureau of information, the rate of complaints concerning late delivery was 30 times higher in 1991 than in 1964. Because the United States Postal Service changed neighborhood routes from a multiple-truck delivery system to a single-truck delivery system between 1964 and 1991, the enormous increase in complaints must be a result of this systematic change.

Which of the following, if true, weakens the conclusion drawn above?

    In 1991, most late-mail complaints were reported to the appropriate United States Postal Service office, whereas in 1964 most were not.

    Even in a multiple-truck delivery system, certain letters will arrive late.

    According to the United States Postal Service bureau of information, most of the complaints concerning late delivery in 1991 were about registered mail.

    The bulk amount of mail processed by the United States Postal Service was not much larger in 1991 than it was in 1964, before the systemic change occurred.

    The change in neighborhood routes from a multiple-truck to a single-truck delivery system sometimes causes enormous increase in the price of stamps.

Summary

·        Most critical-reasoning questions require you to break down an argument. The conclusion is the main point of an argument. The premise is the fact cited in support of the conclusion.

·        The assumption is used to link the premise and the conclusion with each other. Without an assumption, an argument breaks down.

·        To crack a critical-reasoning question, read the question first so you understand the task. Some questions require you to identify the conclusion and the premise of an argument. Others ask you to find the assumption or to strengthen or weaken the argument.

·        After reading the question, break down the argument into its premise and conclusion and, if necessary, the assumption.

·        Try to predict in your own words what the correct answer needs to do in order to answer the question.