I. Modify Arguments

Perhaps one of the most difficult parts of the Critical Reasoning is modifying arguments. In ‘modifying arguments’ type of questions, you will be asked to strengthen or weaken arguments. You can do this by increasing or decreasing the validity of an assumption since assumptions are statements in arguments that are taken to be true.

Language cues for ‘modifying arguments’ questions

  • Most strengthens
  • Most supports
  • Most justify
  • “. . . strengthens . . . except . . .”

Solving ‘modify arguments’ questions

  • In answering questions that ask you to strengthen arguments, find the necessary assumption in the passage because this is often what the correct answer will target.
  • Causal fallacies are commons in this type of questions. Sometimes you have to strengthen or weaken the causal connection between two ideas.
  • When answering questions that ask you to weaken an argument that compares two ideas, try to look for something that will undermine the comparison.
  • Avoid common traps like irrelevant answer choices or statements that require additional facts not present in the passage or question.
  • Keep an eye out for sweeping statements that use words like all, always, never, none, only, and etc. These statements are easier to refute because you need only one exception to disprove the argument.
  • On the other hand, qualifying statements use words like some, sometimes, usually, and probably. These statements make soft claims which make arguments harder to refute.
  • All of the following may be inferred from the passage EXCEPT:

II. Statistical Reasoning

Statistical fallacies are a form of causal fallacies, and these fallacies are relatively common in the GMAT. This is why it is important to familiarize yourself with them so you can avoid committing these fallacies yourself.

  1. Biased Sample Fallacy

The biased sample fallacy is when you draw data from a statistical inference from a sample that is not representative of the population under consideration.

  1. The Texas Sharpshooter

The Texas sharpshooter fallacy is cherry-picking data cluster to suit the assumption you made. Instead of analyzing the data and forming a conclusion, you use your hypothesis to choose which parts of the data will support it.

  1. Insufficient Sample Fallacy

Also known as “hasty generalization,” this fallacy is when you draw a conclusion from an inadequate sample or premises.

  1. Correlation vs. Causation

Correlation refers to a statistical link between two things, while causation is when one thing causes another thing. It is common for test-takers to confuse these two concepts. Some things may be in correlation with each other but are taken as having causal relation.

  1. Confounding Factors

Also known as “lurking variables,” confounding factors are additional factors that may be responsible for a correlation.

  1. Improperly Weighing Cost-Benefit/Advantages

This error in thinking is when one incorrectly weighs the advantages and disadvantages of something. This is an error in one’s evaluation where the cost-benefit of something is not properly analyzed.

  1. Confusing Possibilities and Certainties

This error in thinking occurs when one thinks that just because something is a possibility then it is already a certainty, which is incorrect.

III. Weaken Reasoning

This type of question asks you to find statements that weaken or decrease the strength of an argument. An answer does not necessarily have to refute the argument completely. It only has to make it significantly weaker. The steps for solving this type of question is similar to the steps in solving ‘modify arguments’ questions.

IV. Paradox Questions

A paradox is a statement that is seemingly absurd or self-contradictory at first but may actually be true when investigated further. Paradox questions will ask you to resolve the given paradox or explain how the contradiction can reasonably exist.

Solving ‘paradox questions’

  1. Read the argument carefully and find the paradox or contradiction.
  2. State the paradox or contradiction in your own words.
  3. Use the process of elimination to find the answer choice that will best explain both sides of the paradox or contradiction.

V. Explain Questions

In these questions, you will be asked to provide a premise that will strengthen an argument with faulty reasoning. You will have to explain how an argument could still be true. In other words, you have to present information or a statement that could either significantly strengthen or weaken an argument.

Solving ‘explain’ questions

  1. Read the argument and find the apparent discrepancy, lapse, or contradiction.
  2. State the apparent discrepancy, lapse, or contradiction in your own words.
  3. Eliminate the answer choices one by one to find the answer that best explains the fault or complete the discrepancy in reasoning.
  4. Avoid common trap choices such as choices that simply deny the idea which the question asks you to explain or statements that explain something not directly referring to the passage.

Trick Answer Type: Trick Opposites

The translation of “EXCEPT” is that, of the five choices, all of them fit the condition EXCEPT one of them. On test day, expect to run into a stem that looks like this:

All of the following are reasons to go to law school EXCEPT:

(A) networking with future powerful lawyers
(B) eager to learn tax law
(C) increase your income
(D) impress your friends
(E) hone your poetry skills

This trap involves contradicting the question stem. This trap is very common on Strengthen/Weaken questions where the answer choice does the opposite of what the stem wants:

Here are examples of these deliberate tricks intended to catch students who rush through EXCEPT questions:

  • All of the following may be inferred from the passage EXCEPT:
    Then the GMAT gives one answer that absolutely may be inferred from the passage (which test-takers tend to pick automatically if they forget the “EXCEPT”).
  • The stem asks for an assumption in an argument, and one of the answer choices is a summary of the argument (but not an underlying assumption).
  • Which of the following weakens the argument above?
    Then the GMAT gives an answer choice that obviously strengthens the argument.

Sample Question

Inflation rose by 5.1% over the 2nd quarter, up from 4.1% during the first quarter of the year, and higher than the 3.3% recorded during the same time last year. However, the higher price index did not seem to alarm Wall Street and stock prices remained steady.
Which of the following, if true, could explain the reaction of Wall Street?

  1. Stock prices were steady because of a fear that inflation would continue.
  2. The President announced that he was concerned about rising inflation.
  3. Economists warned that inflation would persist.
  4. Much of the quarterly increase in the price level was due to a summer drought’s effect on food prices.
  5. Other unfavorable economic news had overshadowed the fact of inflation.


This is a paradox because the high inflation report would seem to indicate that the stock market should go down.

A fear that inflation would continue (A), an announcement by the president that he was concerned about inflation (B), economists’ warnings about inflation (C), and other unfavorable economic news (E) would all tend to cause stock prices to decline and cause alarm on Wall Street.

What we are looking for instead is an explanation which suggests why a high-inflation report would not spook the markets. (D) is most appropriate. If most of the quarterly inflation was due to a rise in food prices caused by a drought, then other prices rose less or no more than in the last quarter. Since the drought is probably a temporary phenomenon, it may be expected that inflation will decline next quarter. Thus, there is no cause for alarm on Wall Street, and the high-inflation report should not scare the markets.

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