GMAT Verbal: Critical Reasoning

Building off of the logic required in sentence correction (SC), critical reasoning (CR) is a pure test of pattern recognition and critical thinking skills. Unlike SC, however, foundational knowledge of a topic isn’t necessary. Instead, like all GMAT question types, the key to success is properly identifying what the question stem is asking and then selecting the answer choice that responds appropriately.

The mindset needed to excel at critical reasoning is the same as for golf. Particularly with inexperienced golfers, the affliction of ‘paralysis by analysis’ can take hold. Beginners focus so intently on ‘swing thoughts’ – like remembering to slow down their backswing or to accelerate their downswing - that they forget the most important step of all: making clean contact with the ball.

Similarly, GMAT test prep companies focus on the ‘swing thoughts’ test takers need to be successful on critical reasoning. They tell students to memorize the different kinds of argument types and fallacies, to learn how to dissect stimuli to the sub-premise level, and to read pages of strategic tips instead of making them answer practice problems. While it probably helps them sell books, this type of approach isn’t necessary. All it does is confuse the test taker.

The secret to scoring well on critical reasoning is no different than on any other section of the GMAT: you need to develop a framework and familiarize yourself with it by answering practice problems. On the other hand, if you choose to clutter your mind with unnecessary details, then you’ll surely forget to make contact with the ‘ball’. This post will explain what a successful GMAT CR routine includes and then apply it together so you can answer practice problems on your own.

Basic Strategy

When a CR question appears on the GMAT, follow these four steps:

1. Read the question stem and decide what type of question it is

2. Read the stimulus and identify the conclusion

3. Predict what the correct answer would look like

4. Scan the answer choices and select the equivalent answer

The first step is to determine what type of question is being asked - which we’ll describe in detail in the next section. While illogical, the second step is to read the stimulus. If you know what the question is asking first, you’ll be able to save time by not having to reread the stimulus. After doing so, you’ll be able to determine the argument’s premise(s) and conclusion.

Premise: People are more comfortable in the rain if they wear a hat.

Conclusion: Since I’m in the rain and I like being comfortable, I’ll put on a hat.

Also to note is the stimulus’ tone. Depending on the kind of language used, some answer choices can be eliminated. For example, a stimulus that includes, ‘some people’, isn’t going to be linked to an answer choice that includes the absolutes ‘always’ or ‘never’. While not essential to all CR questions, the higher-level ones require an awareness of tone.

Once you’ve completed the first two steps, a process that should take under a minute, you need to guess what the correct answer choice would look like. For instance, you might predict that based on the conclusion and tone of the stimulus, the correct answer choice to weaken the stimulus would say that hockey can be played in the summer.

At this point, selecting the correct answer choice is the easy part. Simply try to match your prediction with an option that’s provided in A through E. A key distinction of CR is that your task is to select the ‘best’ answer –which means more than one answer might appear to be correct. By predicting what the correct answer should be before reading the answer choices, you can circumvent the test makers’ most commonly used trap.

Question Types

The backbone of step 1, there are four main types of question stems in CR:

1. Weaken/strengthen

2. Must be true

3. Assumption

4. Resolve the paradox

Weaken/Strengthen

‘Weaken’ questions are the most common in CR. They want you to select the answer choice that most weakens the conclusion. It doesn’t have to totally overthrow it, but it should cause the reader to doubt its validity. On the other hand, ‘strengthen’ questions task you with choosing the answer choice that most strengthens the conclusion.

Must be true (MBT)

The MBT question type asks you to select the answer choice that’s inferred by the conclusion. You must ask yourself if the answer choice can be proven or validated by what’s in the stimulus. It’s important to note that this inference must exist, not just be possible. While Adidas likes to remind us that “Anything is possible,” on MBT problems, it needs to be more certain than that.

Assumption

‘Assumption’ questions are a derivative of MBT questions. Instead of using the conclusion to prove the answer choice, you use the answer choice to prove the conclusion. The ‘assumption’ properly outlined in the correct answer choice will be absolutely necessary to uphold the conclusion. Note that you’ll never have to assume something outside of the scope of the question; simply use it to deduce the author’s method of reasoning.

Resolve the paradox (RTP)

For RTP questions, the stimulus will present a situation in which two items combine for an unexpected result. Your job is to choose the answer choice that explains how this is possible.

In addition to the four question types outlined above, there are a few more that are less commonly tested. Specifically, they are ‘boldfaced’, ‘flaw in the reasoning’, and ‘method of reasoning’.

‘Boldfaced’ questions highlight two sections of a stimulus and ask you to define what their purpose is in the argument. For example, the first is a claim made by the author’s opponent and the second is the conclusion the author makes to refute this claim.

‘Flaw in the reasoning’ questions require you to select the answer choice that points out why the conclusion isn’t persuasive. Perhaps the author left out a key assumption or is relying on a causal argument.

‘Method of reasoning’, also known as ‘mirroring’, is a game of comparison; if the author argues this way, then it holds that he or she would argue this way about a different topic.

Putting it all together

Let’s illustrate the routine and strategies discussed above with a practice question:

A cost-effective solution to the problem of airport congestion is to provide high-speed ground transportation between major cities lying 200 to 500 miles apart. The successful implementation of this plan would cost far less than expanding existing airports and would also reduce the number of airplanes clogging both airports and airways.

Which of the following, if true, could proponents of the plan above most appropriately cite as evidence for the soundness of their plan?

a) An effective high-speed ground-transportation system would require major repairs to many highways and mass-transit improvement.

b) One-half of all departing flights in the nation’s busiest airport head for a destination in a major city 225 miles away.

c) The majority of travelers departing from rural airports are flying to destinations in cities over 600 miles away.

d) Many new airports are being built in areas that are presently served by high-speed ground-transportation systems.

e) A large proportion of air travelers are vacationers who are taking long-distance flights.

Reading the question stem, we can deduce that the test maker wants us to select the answer choice that strengthens the author’s argument. While sometimes the stimulus will actually say ‘strengthen’ or ‘resolve the paradox’, often you’ll have to interpret what it’s asking - much like how you have to translate word problems in quant. Evidence strengthens an argument, so by selecting such an answer choice, that’s exactly what you’d be doing.

Next, read the stimulus. The author is arguing that to solve airport congestion, high-speed ground transportation should be built between major cities. That argument sounds reasonable; what’s its tone? (This is a good example of when the tone of a sentence might not affect which answer choice you pick.) At least for this question, the author has a balanced tone.

What would an answer choice that strengthens the author’s argument that, “High-speed ground transportation should be built around major cities,” look like? There could be several options, but the most crucial element is usage. If ground transportation is available in a 200-500 mile radius, are trips of that length demanded by travelers? If the most demanded trip is shorter or longer, the proposed solution might not solve this problem.

Answer choice A can be eliminated because there’s no mention of the cost of expanding airports; what ‘major’ repairs would it be compared against? Answer choice C can be eliminated because the argument is addressing the transportation needs of major cities, not rural ones. Answer choices D and E can be eliminated because this information is irrelevant. That leaves answer choice B, which is conveniently, the correct answer to this question.

CR doesn’t have to be that hard. Take a measured approach and ask yourself what answer choice would logically fit the question stem’s need. For a strategy to be a good one, it has to be viable regardless of a question’s difficulty. Use practice problems to apply the routine outlined above so that you can confidently identify the conclusion, question type, and correct answer in no more than two minutes. Do that and you’ll be a Dr in CR!