GMAT: Critical Reasoning

Argument Structure

PREMISE + (ASSUMPTION) = CONCLUSION

Premise: stated pieces of information or evidence that provide support for the conclusion (facts, opinions or claims).

Assumption: unstated parts of an argument that are necessary to reach the given conclusion. NEVER stated in the written argument.

Conclusion: the main point of the argument, logically supported by the assumptions and premises. In the form of an opinion or claim.

Identifying the Parts of an Argument

1. Look for the conclusion.

- often the last sentence of an argument, but sometimes the first.

2. Find the premises that lead to the conclusion.

- provide ALL the pieces of information written in the argument.

- provide evidence that supports or leads to the conclusion.

3. Determine any assumptions if needed.

- will NEVER find them stated in the written argument.

Finding the Conclusion

Presented in 3 common ways, so read the question first!

1. Question contains the conclusion.

2. Question hints at the conclusion in the argument.

3. Argument contains an obvious conclusion, indicated by a clear signal word.

Some GMAT questions ask you to draw the conclusion using only the premises in the passage. The conclusion will be in the answer choices.

Signal Words for Argument Parts

Conclusion:

Therefore

As a result

Suggests

It follows that

Indicates

Accordingly

So

Consequently

Thus

Hence

Should

Premises:

Since

Due to

As a result of

Because

Given that

As

Alternate Way to Find the Conclusion

Only use this method when the primary patterns do not apply.

1. Identify all claims from facts (which can be proven).

A) predict the future - will, should, can be expected to, could result in, are likely to

B) subjective opinion - anything that cannot be proven

C) cause & effect - if...then, as a result of, because of, since, so

If you find only 1 claim, that is the conclusion. If you find more than 1 claim, go to step 2.

2. Use the "Therefore" test.

If you have two claims X & Y, ask yourself which leads to the other.

A) "X, therefore Y". If this works, Y is the conclusion.

B) "Y, therefore X". If this works, X is the conclusion.

The deduction that takes place last logically in the sequence of events is the conclusion.

Other words to use: so, thus, as a result

How to Diagram an Argument: The T-Diagram

1. Focus on the essential meaning.

2. Use EXTREME shorthand.

3. Keep terms the same - try to keep exact wording of key points.

4. Make sure you understand what you are writing.

The T Diagram:

1. Draw a large T, leaving more room on the left "pro" side than the right "con" side.

2. Look for the conclusion and write it on the top of the T.

3. Read the argument sentence by sentence. Write any pro premises on the left and cons on the right. Put background information under the T. Put assumptions in brackets [ ].

Diagramming Efficiently

1. Abbreviate anything you can but don't abbreviate so much that you change or lose the argument.

2. Underline key words, details and boundary words.

3. Use arrows to indicate cause and effect relationships.

4. Identify point of view with a colon to indicate WHO is advocating the position or plan.

5. Signal any change of direction in the passage with the word BUT in capitals.

6. Develop your own abbreviations.

Major Question Types

1. Find the assumption.

2. Draw a conclusion.

3. Strengthen the conclusion.

4. Weaken the conclusion.

5. Explain an event or discrepancy.

6. Analyze the argument structure.

7. Evaluate the conclusion.

8. Resolve a problem.

9. Provide an example.

10. Restate the conclusion.

11. Mimic the argument.

Identifying the Question Type

When reading any question stem, try to classify the problem. Then, as you diagram, proactively find answers for the question type.

Read the question stem first. If it is not immediately helpful, do not dwell. The process of diagramming will generally clarify the question stem.

"Except" and "Fill in the Blank" Questions

In order to clarify a question stem with EXCEPT, rephrase the EXCEPT statement into a question, inserting the word NOT and eliminating the word EXCEPT.

Ex: "Each of the following helps to explain event X except..." turns into

"Which one does NOT explain X?"

"Fill in the Blank" is a disguised version of a known question type. Once you recognize what type it is, use the standard strategies for that type.

Boundary Words

They limit the scope of an argument and can be useful in identifying incorrect answer choices.

They provide nuances to the argument, which can help you make some answer choices correct or incorrect.

When diagramming, be sure to include boundary words and underline them.

Extreme Words

Always, never, all,none, etc.

They make the argument very broad or far-reaching, making it susceptible to attack.

Note any extreme language used in premises or conclusions with an (!).

This strategy ONLY applies to words in the argument. Extreme words can be found in the answers if supported by the argument directly.

Answer Choices: Process of Elimination

Use your paper to visibly eliminate answer choices A-E. Cross out incorrect choices and circle the correct answers.

Check all of the answer choices even if you believe you have found the correct one. You may find that another answer choice is potentially correct.

Boundary & Extreme Words in Answer Choices

Extreme words make the answer choices incorrect, unless the argument explicitly justifies/states extreme words.

A correct answer choice must be 100% true.

When you see boundary or extreme words in an answer, ask "what is the most extreme example I can think of that would still fit the wording of this answer choice?" Then, using the conclusion and the question asked, see whether your extreme example allows you to eliminate that answer choice.

Find the Assumption Questions

Commonly uses words "assumption, assume, flaw or questionable".

Assumptions serve as a necessary bridge between the premises and the conclusion.

The correct answer choice of an assumption question must be necessary to the conclusion of the argument.

Assumption: Ties to the Conclusion

Look for the assumption to:

1. Bridge agap between any premise and the conclusion.

2. Support/strengthen/validate the conclusion.

The answer doesn't have to be the only necessary assumption. The right answer is often "necessary but not sufficient."

If the assumption in the correct answer were NOT true, you could reject the conclusion on that basis alone.

The correct answer doesn't need to make the conclusion definitely true but only somewhat likely to be true; should fit readily into the structure of the argument.

Negating an assumption is a powerful technique. If an answer choice in a question is negated and the argument becomes nonsensical, then the answer choice is almost certainly correct.

An argument might depend on several assumptions, any of which could be the answer. However, only one of these will be given in the answer choices.

Categories of Assumptions

1. Fill in a logic gap.

- "how do we logically get from Point A to Point B?"

- key words: therefore, because, for this reason, etc.

- fact-based or background information; occasionally reflects an opinion or claim

2. Establish the feasibility of the premises of an argument.

- Reflects opinions or claims and that these are true or that a sequence of events will occur in a way the argument assumes.

3. Eliminate alternate paths to reach a given conclusion.

- uses some type of superlative qualifier like only/best/worst way

- there shouldn't be another way or better/worse way.

4. Can eliminate alternate causes for a given conclusion.

- cause and effect conclusions; correlation is not causation.

- look for an assumption that eliminates an alternate model of causation

- you must rule out the causality in the other direction

Assumptions: Wrong Answer Choices

The answer choice MUST be true!

A. No ties to the conclusion.

- provides an assumption that is not actually necessary for the conclusion to be logically valid.

- breaks up a category subtype (bk 6, pg 62-63)

B. Wrong direction

- answer choice provides the opposite of what you are looking for

C. Switching terms

- answer choice replaces a fundamental term with something that seems like a synonym or introduces extreme words

- common between numbers, percentages and proportions

D. Addresses the premise only

- explains or leads to a premise instead of the conclusion

E. Follow on

- follows on from the conclusion instead of identifying an assumption that underlies the conclusion

LEN: Least Extreme Negation Technique

What do you do when two or more answer choices are very tempting? Use the Least Extreme Negation (LEN) technique.

- negate answer choices to see whether the argument fails

- use the least extreme negation possible.

If the conclusion can still follow the premises when using LEN, the answer choice is wrong. If the given premise no longer supports the conclusion after LEN, the answer choice is correct.

LEN Examples

- Always, only, all >> insert not necessarily or sometimes... Not

- Never, none, not one, not once >> at least one, at least once

- Some, a few, several >> no, none

- Sometimes, on occasion, often >> never

- At least, at most, more than, less than >> change to the mathematically opposite term

- Best, worst, greatest, smallest, highest >> not necessarily

When in doubt of how to negate, use "not necessarily."

Draw a Conclusion

Conclude something from a given set of premises.

- the conclusion you draw must be true as a result of only the given premises; it should not require any additional assumptions.

Sample question stems:

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

"Which of the following conclusions can best be drawn from the information above?"

Draw a Conclusion: Stay Close to the Premises

The conclusion you select should be supported by at least some of the premises. The conclusion does NOT need to address all of the premises. A correct answer may be a mathematical or logical deduction.

In this type of question, the entire body of the argument represents premises. The correct conclusion must always be a provable fact. This, it will generally restate a premise, sometimes in a mathematically equivalent way.

Use Real Numbers, Make an Inference

If an argument involves percentages, use real, concrete numbers.

The words inference, assertion, prediction and claim are all synonyms for conclusion.

Wrong Answer Choice Types: Draw a Conclusion

A. Out of Scope

- answers require you to assume at least one piece of information not explicitly presented in the argument.

B. Wrong Direction

- provides a conclusion that is opposite of what the argument says.

C. Switching Terms

- proposes faulty mathematical or logical reasoning.

- make sure that any substituted expressions are truly synonyms

Weaken the Conclusion

Most common among critical reasoning questions.

Correct answers do NOT need to make the conclusion false or invalid; just needs to make it less likely that the conclusion is valid.

Correct answers will:

1. Expose a faulty or tenuous assumption OR

2. Negatively impacts the conclusion directly

Weaken the Conclusion: Argument/Counterargument

Arguments contain 2 opposing points of view. Assess answer choices by holding them in opposition to the conclusion or one of its assumptions.

1. Identify the conclusion from the point of view of the author.

2. Note the counter-claim and it's proponent.

3. Create a modified T-diagram with the central column extended upward, splitting the conclusion. Put the author's POV on the left side and the counter-claim on the right. Fill in the pros and cons of the author's argument as usual.

Strengthen the Conclusion

To strengthen an argument, look for an answer choice that fixes a weakness of the conclusion, validates an assumption, or introduces new supporting evidence.

A premise can strengthen or support a conclusion without being necessary for that conclusion.

On the EXCEPT type of question, eliminate answer choices that strengthen the conclusion. Simplify them by eliminating the word "except" and replacing them with "not."

S-W-Slash Chart

To help the process of elimination:

1. Write down letters A-E.

2. Evaluate each answer choice and note whether

a. It strengthens the conclusion with an S

b. it weakens the conclusion with a W

c. Is irrelevant to the conclusion with a slash through it

3. If an answer indirectly or arguably strengthens or weakens the conclusion, use a lowercase s or w

Argument is a synonym for conclusion.

Strengthen the Conclusion: Wrong Answer Choice Types

1. No Tie to the Conclusion

- tied to a premise and provides unnecessary information about a premise

- if the premise is already a stated fact, it doesn't need support

- make sure the answer choice is not simply related to the conclusion but supports it

2. Wrong Direction

- many answer choices weaken the argument instead of strengthening it

- make sure to note the question type so as to choose the correct answer

Weaken "EXCEPT" Questions

An answer choice that weakens the conclusion without requiring significant leaps of logic is likely correct.

Use an S-W-slash chart on EXCEPT questions with confusing wording. Four answer choices will weaken - one will not.

The correct answer choice sometimes strengthens the conclusion while in other cases the correct answer is irrelevant to the conclusion.

Weaken: Wrong Answer Choice Types

A. No tie to the conclusion

- wrong answer choices provide unnecessary information about a premise

- make sure answer choices are not simply related to the conclusion but also weaken it

- an answer choice can seem realistic, but only need to determine whether it weakens the argument

B. wrong direction

- make sure to note if a question is strengthen or weaken the conclusion so as to not mistakenly choose the wrong answer.

- use an S-W-slash chart

Minor Question Type: Explain an Event or Discrepancy

- Poses two seemingly contradictory premises and find the AC that best reconciles them.

- Question will indicate the discrepancy or provide a keyword pointing to it in the argument:

yet, however, nonetheless, paradoxically, surprising because...

Arguments will only have premises, no conclusion.

Look for the AC that gives a new, fact-based premise that shows why the discrepancy is not one.

- after you add it to existing premises, it shoul make sense all together

- correct AC fills a logical hole in the argument, allowing all premises to be true without a perceived conflict

Be careful not to misread and think you are supposed to explain why the discrepancy exists - just explain why it's not a real discrepancy.

MQT: Analyze Argument Structure

Describe the role of a part or parts of an argument.

- often use argument/counterargument structure (use modified T-diagram)

Don't spend too much time - eliminate a few choices and move on.

Two boldfaced statements - determine the role each one plays in the argument.

1. Conclusion (position, assertion)

2. Supports conclusion

3. Weakens conclusion

Classify statements according to these. Note what each statement is, then go through answer choices and assess if they match.

Alternative approach (faster):

Read the passage and label each boldface as Fact, Opinion, or Conclusion.

Skim each answer choice, only looking for terminology matching F, O, C.

Eliminate AC that don't match F, O, C classification.

MQT: Various Types

Evaluate the Conclusion

- identify information that would help evaluate the validity of a given conclusion

- the correct AC will provide a way to TEST the conclusion

Resolve a Problem

- solve a problem posed by the premises

- correct AC should directly counteract or fix a given problem. Tend to appear as a new premise

- wrong AC will address some piece of the argument but not counteract or fix the problem. Some wrong AC will reinforce the problem exists or make the problem worse

Provide an Example

- select a situation that best exemplifies the conclusion

Restate the Conclusion

- identify the conclusion and choose the best AC that restates or paraphrases it

Mimic the Argument

- analyze the logical flow of a argument and choose the AC that most closely mimics the argument flow or structure

- be sure to not spend too much time