In critical reasoning, there are six main questions types: conclusion, inference, assumption, strengthening, weakening, and boldface.

Conclusion and Inference Questions

Conclusion questions present a list of facts from which you are asked to draw a conclusion. The conclusion should repeat or synthesize the information. So, do not use outside knowledge and include information that was not presented when drawing the conclusion.

Strategy: First, paraphrase (or diagram) the information presented and then aim to stay within the scope of this information.

Tip: An extreme conclusion (containing such words as only, always, never, any, all etc.) cannot be drawn from premises whose wording is not equally extreme.

Example Conclusion Question:

In recent years, nursing-related health care jobs have come to be among the more sought-after positions in the medical industry. From 2007 to 2010, an average of 22 percent of nursing positions remained unfilled per year, while hiring rates remained unchanged at an average of 850 per 1000 candidates per year. But in the last five years, the percentage of open nursing positions has dropped to 11 percent, while hiring rates have also declined by 14 percent.

If the statements above are true, which of the following conclusions can be most properly drawn?

A) Over the last five years, the average retirement age in the field of nursing has increased.

B) The proportion of college students entering the nursing-related fields is higher today than it was in 2007.

C) Whenever the job market becomes more competitive, the medical field becomes more attractive to job-seekers.

D) Between 2007 and 2010, hospitals maintained a higher average nurse-to-patient ratio than they do today.

E) The smaller the hospital, the smaller its training programs and acceptance rates to new nursing positions.

Solution:  

Paraphrase: The number of job openings in the field of nursing is decreasing, but there are also fewer nurses being hired.

Retirement age has an immediate effect on the percentage of nursing positions filled; the later nurses retire, the fewer job openings there will be, making A reasonable. The number of students studying nursing, the attractiveness of the job market, nurse-to-patient ratio, and relative hospital size would all bear no immediate relation to job openings, eliminating B, C, D, and E. So, the correct answer is A.

Example Inference Question:
At AJ Fashion Warehouse, the accessories department accounted for approximately 30 percent of profits last quarter, more than any other single department. Yet, the accessories department also accounted for only 10 percent of dollar sales, less than the proportion of dollar sales for any other department.

Which of the following can properly be inferred regarding the last quarter?

A) The retailer’s revenues have remained unchanged throughout last quarter.

B) The fashion industry has seen greater competition in accessories than in apparel.

C)The accessories department has realized higher profits per dollar of sales than any other department.

D)The accessories department has realized lower profits per dollar of sales than any other department.

E) Top-brand accessories were key to the retailer’s economic viability this past quarter.

Solution:
Paraphrase: While generating relatively little revenue, the accessories department accounted for a large portion of profits.

Nothing regarding total revenue, competition, or brands was mentioned, eliminating A, B, and E. High profits generated from small revenues would indicate that the profits per sale are high, eliminating D. So, the correct answer is C.

Assumption Questions
Strategy: Paraphrase the conclusion. In your head, add the words “as long as” to the end of the conclusion and then each answer choice. In light of the premises, the resulting sentence should flow logically without requiring extra information that was not written.

Tip: If you’re unsure as to whether the answer is necessary to the conclusion, try negating the answer. If the conclusion is still valid when you negate the answer, then it is not necessary to the conclusion and is not an assumption. 

Example Assumption Question:

Country X through its history has produced its own maize and poultry. However, as per-capita income in Country X has approached the world average, per-capita consumption of poultry has also crept toward the world average, and it takes several pounds of maize to produce one pound of poultry. Therefore, since per-capita income is increasing, whereas domestic maize production is not expected to rise, Country X will soon have to import either maize or poultry or both.

Which of the following is an assumption underlying the argument?

A) The total acreage devoted to maize production in Country X will not decrease significantly.

B) The population of Country X has remained relatively stable during the country’s years of growing prosperity.

C) The per-capita consumption of poultry in Country X is roughly the same across all economic sectors.

D) In Country X, neither poultry nor maize is subject to government price controls.

E) People in Country X who increase their consumption of poultry will not dramatically decrease their consumption of maize.

Solution:

Paraphrase of the conclusion: To meet the rising demand for poultry, Country X must import maize and/or poultry….

A)  To meet the rising demand for poultry, Country X must import maize and/or poultry as long as the acreage devoted to grain production will not decrease.

B)   To meet the rising demand for poultry, Country X must import maize and/or poultry as long as the population has remained constant.

C)   To meet the rising demand for poultry, Country X must import maize and/or poultry as long as the per-capita consumption of poultry is the same across all income levels.



D)  To meet the rising demand for poultry, Country X must import maize and/or poultry as long as neither poultry nor maize is subject to price controls.

E)   To meet the rising demand for poultry, Country X must import maize and/or poultry as long as the people who increase their consumption of poultry will not decrease their consumption of maize.

Consumption of maize is the only factor that directly affects demand for maize, and therefore E, the correct answer, is the only answer on which the conclusion wholly relies.

Weakening Questions

Strategy: Paraphrase the negation of the conclusion, by adding the word “not”. Then, in your head, add the word “because” followed by the answer choice. The resulting sentence should flow logically.

Tip: If the argument is causal, the correct answer often offers an alternative cause. If the argument is by analogy, the correct answer often identifies a difference between the parties. If the argument is statistical, the correct answer often identifies a difference between the sample group and the whole group that is addressed in the conclusion.

Example Weakening Question:
According to the results from a voluntary survey of 1000 residents selected from the greater metropolitan area of Tuptin last year, 74% had attended West Tuptin High School and thereafter gained successful employment in automobile manufacturing, the city’s most thriving industry. In another survey, also conducted a year ago, 81% of residents from the same area claimed to have no interest in fields related to mechanics. Clearly, Tuptin High School is driving students toward careers in manufacturing irrespective of students’ actual interests.

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

 A) The participants in the surveys were motivated to answer honestly the questions posed.

B) The majority of the respondents in the second survey attended high schools other than West Tuptin High School.

C) Adjacent cities do not have vocational schools that train students for particular professions starting from a relatively young age.

D) The city’s oldest industry, the automobile manufacturing industry in Tuptin was established over 50 years ago.

E) The majority of participants in the first survey also claimed to have been pleased with their high school experience.

Solution

Paraphrase of negated conclusion: Tuptin High School graduates WERE interested in manufacturing.

A) Tuptin High School graduates WERE interested in manufacturing because the survey questions were answered honestly.

B)   Tuptin High School graduates WERE interested in manufacturing because the people who said that they were not interested in the industry did not go to Tuptin High School.

C)   Tuptin High School graduates WERE interested in manufacturing because there are no training programs at nearby schools .

D)  Tuptin High School graduates WERE interested in manufacturing because the industry is old.
E)   Tuptin High School graduates WERE interested in manufacturing because Tuptin High School graduates liked Tuptin High School.

This is a statistical argument in which the respondents to the second survey are assumed to representative of Tuptin High School graduates. Thus, the suggestion that the respondents to the second survey, who said that they were not interested in manufacturing, did not attend Tuptin High School would weaken the conclusion. So, the correct answer is B.

Strengthening Question

Strategy: Paraphrase the conclusion. Then, in your head, add the word “because” followed by the answer choice. The resulting sentence should flow logically. 

Tip: If the argument is causal, the correct answer often eliminates an alternative cause. If the argument is by analogy, the correct answer often identifies a similarity between the parties. If the argument is statistical, the correct answer often identifies a similarity between the sample group and the whole group that is addressed in the conclusion.

Example Strengthening Question:
Walkit sandals are made out of a revolutionary material that is made from a unique combination of natural rubber, cork, and cotton fiber, endowing these flexible, breathable sandals with unmatched durability. Consider that over three quarters of people who purchased Walkit sandals within the past five years are today still using the same pair they bought, while the average sandal made by any other leading brand lasts a maximum of three years.

Which of the following, if true, most strengthens the argument?

(A) The price of Walkit sandals, when adjusted for inflation, has decreased little over the past five years.

(B) In the past two years, there has not been a dramatic increase the volume of sales of Walkit sandals.

(C) Because Walkit is a high-fashion brand, owners of Walkit sandals rarely wear them on outdoor trips involving long walks or hikes.

(D) The sole dynamics of Walkit sandals have changed considerably over the past five years.

(E) Competing brands target a different age group than does Walkit, which is designed primarily for people aged 35 to 45.

Solution

Paraphrase of conclusion: Durability is the reason that people are still wearing their Walkits purchased within the last five years.

A)  Durability is the reason that people are still wearing their Walkits purchased within the last five years because the price of Walkits has not changed.

B)  Durability is the reason that people are still wearing their Walkits purchased within the last five years because the Walkits people are wearing are not new.

C)  Durability is the reason that people are still wearing their Walkits purchased within the last five years because Walkits are not worn on long walks.

D)  Durability is the reason that people are still wearing their Walkits purchased within the last five years because no changes have been made to the soles.

E)   Durability is the reason that people are still wearing their Walkits purchased within the last five years because competing brands target a different age group.

 That Walkits have not become cheaper, that Walkits are not used on long walks, that the soles have been changed, and that there is little competition are all alternative reasons as to why Walkits purchased within the last five years are still in use, eliminating A, C, D, and E. That many of the Walkits in use are new would be an alternative reason as to why the Walkits are still in use, a reason that is eliminated in answer B, thus strengthening the conclusion. So, the correct answer is B.

Bold-Face Questions

 Strategy: Do not make the mistake of trying to discover the relationship between the two portions in bold. You must identify the role of each portion in bold within the context of the whole argument.  Therefore, try to identify every sentence as a premise, conclusion, example, counterexample, or explanation as you read.

Tip: Bear in mind the terminology used: premises are also called evidence, facts, pattens, and generalizations: conclusions are also called claims, arguments, and predictions.

Practice Bold-Face Question

Business consultant: It is generally true that computer stores that offer a greater variety of models experience a greater volume of sales than those with more limited selections.  It is also true that computer stores that achieve a higher volume of sales tend to reduce their prices to maximize their competitiveness on the market.  However, diversifying the product line at Kat’s Computers would most likely reduces sales and prevent competitive pricing.  Kat’s Computers is a boutique store catering to a niche market, and if its selection were expanded, it would lose customers to larger competitors with the same selection, customers who were looking for specialized products.

In the business consultant’s argument, the two portions in bold face play which of the following roles?

A)  The first is a generalization that the consumer advocate accepts as true; the second is presented as a consequence that follows from the truth of that generalization.

B)  The first is a pattern of cause and effect that the consumer advocate argues will be repeated in the case at issue; the second acknowledges the circumstance in which that pattern would not hold.

C)  The first is a pattern of cause and effect that the consumer advocate predicts will not hold in the case at issue; the second offers a consideration in support of that prediction.

D)  The first is evidence that the consumer advocate offers in support of a certain prediction; the second is that prediction.

E)   The first acknowledges a consideration that weighs against the main position that the consumer advocate defends; the second is that position.


Solution
The first sentence, saying that variety generally results in greater sales, is a premise. The second sentence, saying that a higher volume of sales is usually accompanied by the lowering of prices, is also a premise (a general fact). The third sentence, saying that if Kat Computers diversifies, sales will drop and prices will remain high, is the conclusion. (Note the key words, however and would.) The third sentence, saying that because Kats is a boutique that will suffer from competition with large store if it diversifies, explains the conclusion. Thus, the first bold face is a premise that goes against the conclusion, and the second boldface explains the conclusion. So, the correct answer is C.