Critical Reasoning

Manjyot

A Critical Reasoning question is presented as a short paragraph, followed by one or two questions. The short paragraph is an argument. An argument consists of three parts:

i) the premise – the evidence
ii) the conclusion – the main point of the argument and
iii) an assumption – the unstated or missing premises with out which the argument would be untenable.

In certain cases the conclusion may not be given and the question may require that you supply the conclusion.
The premises are pieces of evidence that the author uses to arrive at the conclusion. The conclusion is valid depending on the strength of the premises or evidences.

Let’s look at an example to understand these terms better.

Revenue from this magazine is at an all time low. Newsstand sales are dropping and there are no new subscribers. Therefore sweeping editorial changes are necessary if the magazine is to survive.

Conclusion: Sweeping editorial changes are necessary for the magazine to survive.

Premises: Revenue down
Newsstand sales low
No new subscribers

Assumption: Only old editorial policy was responsible.

Structural clues that help you locate a conclusion in an argument.
Certain key words can help you isolate the conclusion and the evidence in a stimulus; clues that signal evidence includes - since, because, due to etc.
Clues that signal conclusion include – so, therefore, thus, consequently, hence, as a result etc.
Basic Approach
Always look at the question first.

The basic question types are:

? Find conclusion
? Supply conclusion
? Identify assumption
? Strengthen argument
? Weaken argument
? Find an inference
? Mimic argument

Find the conclusion
In this question type the conclusion is already given. You have to choose from the choices the statement that is already given in the passage as the conclusion of the argument. Look out for key words like hence, so, thus, therefore etc.
At the same time conclusion may also begin without these key words.

Illustration
When young students first look at modernist abstract painting, their eyes are assailed by a seemingly meaningless mass of squiggles. It is only after a study of the history of art and the forces which led up to abstraction that it is possible to appreciate the intellectual sophistication of modern art. Thus, a high-school study of modern art should always begin with a study of the history of art.

Which of the following is the main point of the passage above?
A. To understand the history of art, it is necessary to study modern art.
B. Young students are unable to appreciate fully the complexities of modern art.
C. An understanding of the history of art is essential to an understanding of modern art.
D. To understand abstract art, students must first study the history of art.

Analysis:
Premise #1 : Students don’t understand modern art.
Premise #2 : To understand modern art it is necessary to study art history
Conclusion: Students of modern art must first study art history.

Answers: A. Reverses P # 2 B. P # 1 C. P # 2 D. correct answer

Supply the conclusion
In this question type the argument consists of merely a set of evidences. You have to supply the conclusion. This implies that the answer is not a sentence given in the passage but must include and rest on all the evidences.

Illustration
Fewer elected officials are supporting environmental legislation this year than at any time in the last decade. In a study of thirty elected officials, only five were actively campaigning for new environmental legislation. This comes at a time when the public’s concern for the environment is growing by leaps and bounds.

Which of the following conclusions is best supported by the passage above?

A. More elected officials are needed to support environmental legislation.
B. Elected officials have lost touch with the concerns of the public.
C. The five elected officials who actively campaigned for new environmental legislation should be congratulated.
D. If the environment is to be saved, elected officials must support environmental legislation.

Note: 1. Answer not a sentence from passage.
2. The answer must include and rest on all premises.

Analysis
Premise #1 : Fewer elected officials are supporting environmental legislation.
Premise #2 : Public concern for the environment is growing.

Answers:
A. Ignores premise #2
B. Ignores environment
C. Ignores public concern
D. Correct answer.

Find the assumption
To answer this question, you have to identify the conclusion that is already given in the paragraph. An assumption is a statement that is not given as the premise but is required if the conclusion has to be valid. With out the assumption we cannot arrive at the conclusion. As the assumption is an unstated premise, the answer is not a statement given in the paragraph. Choose the choice that would connect to the conclusion as choice, therefore conclusion.
i.e. Assumption = choice, therefore conclusion
Illustration
Many people believe that gold and platinum are the most valuable commodities. To the true entrepreneur, however gold and platinum are less valuable than opportunities that can enable him to further enrich himself. Therefore, in the world of high-finance, information is the most valuable commodity.
The author of the passage above makes which of the following assumptions?
A. Gold and Platinum are not the most valuable commodities.
B. Entrepreneurs are not like most people.
C. The value of information is incalculably high.
D. Information about business opportunities is accurate and will lead to increased wealth.

Approach:
i. There could be several assumptions.
ii. You are required to find the assumption on which the conclusion depends.

Analysis
Conclusion: In the world of high finance information is the most valuable commodity.

Answers
A. Irrelevant B. Irrelevant C. Same as conclusion D. Correct answer.

In strengthen - weaken the argument, the type of premises given should be examined. The premises could be presented in the form of
statistical data – numbers, percentages, ratios etc.
causal data - that is the data may be in the form of cause- effect relationship, or
analogy – arriving at a conclusion through likening it to a similar situation.

Strengthen argument
Here the conclusion is already given in the argument. One of the choices if true further supports or reinforces the conclusion. This means that the conclusion is further strengthened if a choice is true.
The questions is phrased in one of the following ways:

Which of the following, if true, strengthens the argument?
Which of the following, if true, least weakens the argument?
Which of the following, if true, adds credence to the argument?
Which of the following, if true, reinforces the argument?

Illustration
It has recently been proposed that we adopt an all volunteer army. This policy was tried on a limited basis several years ago, and was a miserable failure. The level of education of the volunteers was unacceptably low, while levels of drug use and crime soared among army personnel. Can we trust our national defense to a volunteer army? The answer is clearly, “No”.
Which of the following statements, if true, most strengthens the author’s claim that an all volunteer army should not be implemented?

A. The general level of education has risen since the first time an all volunteer army was tried.
B. The proposal was made by an organization called Citizens for Peace.
C. The first attempt to create a volunteer army was carried out according to the same plan now under proposal and under the same conditions as those that exist today.
D. A volunteer army would be less expensive than an army that relies on the draft.

Approach:
Look out for 3 types of logic.

1. Statistical 2. Analogy 3. Causal

Analysis: In the above argument the logic is analogy. “the idea did not work then, it won’t work now”.

Answers:
A. Weakens B. Irrelevant C. Correct answer D. Irrelevant

Weaken the argument
In this question type the conclusion is already in the argument but with a questionable assumption. One of the choices if true, weakens the conclusion.
The question is phrased in one of the following ways.
Which of the following, if true, weakens the conclusion?
Which of the following, if true, least strengthen the argument?
Which of the following, if true, jeopardizes the argument?
Which of the following, if true, questions the validity of the argument?
Which of the following, if true, damages the argument?

Illustration
The recent turn around of the LEX corporation is a splendid example of how an astute chief executive officer can re-channel a company’s assets toward profitability. With the new CEO at the helm, LEX has gone, in only three business quarters, from a 10 million dollar operating loss to a 22 million dollar operating gain.

A major flaw in the reasoning of the passage above is that
A. The passage assumes that the new CEO was the only factor that affected the corporation’s recent success.
B. The recent success of the corporation may be only temporary.
C. The chief executive officer may be drawing a salary and bonus that will set a damaging precedent for this and other corporations.
D. the author does not define ‘profitability’.

Approach : Look out for the type of logic
1. Statistical 2. Analogy 3. Causal

Analysis
The logic is causal.
Cause : CEO, Effect : Turnaround

Answers
A. Correct answer
B. Irrelevant
C. Irrelevant
D. Irrelevant

Manjyot

Find the inference
In this question type the conclusion is already given. If the statements in the argument are true, one of the choices also must be true. If there are two premises it is possible for us to make two inferences.
The questions appear as follows:
If the statements in the argument are true, which of the following must also be true?
Which of the following can be inferred from the passage?
Which of the following is implied in the passage?

Illustration
In film and videotape, it is possible to induce viewers to project their feelings onto characters on the screen. In one study when a camera shot of a woman’s face was preceded by a shot of a baby in a crib, the audience thought the woman’s face was registering happiness. When the same shot of the woman’s face was preceded by a shot of a lion running toward the camera, the audience thought that the woman’s face was registering fear. Television news teams must be careful to avoid such manipulation of their viewers.

Which of the following can be inferred from the passage?

A. Television news teams have abused their position of trust in the past.
B. The expression on the woman’s face was, in actuality, blank.
C. A camera shot of a baby in a crib provoked feelings of happiness in the audience.
D. Audiences should strive to be less gullible.

Approach:
1. Inferences often have very little to do with conclusion.
2. For each premise you can have an inference.
Answers:
A. Outside scope
B. Outside scope
C. Correct answer
D. Outside scope

Another possible inference is
A camera shot of a lion provoked feeling of fear in the audience.

Mimic the argument: Here one of the choices is similar / parallel to the given argument in logic and structure.

Illustration
World class marathon runners do not run more than six miles a day when they are training. Therefore, if you run more than six miles a day, you are not world-class.

Which of the following statements supports its conclusion in the same manner as the argument above?

A. Sprinters always run in the morning. If it is morning, and you see someone running, it will not be a sprinter.
B. Paint never dries in less than three hours. If it dries in less than three hours it is not paint.
C. Little league games are more fun for the parents than for the children who actually play. Therefore, the parents should be made to play.
D. If a car starts in the morning, chances are it will start again that evening. Our car always starts in the morning, and it always starts in the evening as well.

Approach:
Simply terms
If A not B, if B not A

Analysis
A. If A, B. If B not A
B. If A not B. If B not A
C. If A, B not C.
D. If A, B. A therefore B