Foundations of Critical Reasoning and Argument Analysis

Review questions

Integrated summary: Foundations of Critical Reasoning and Argument Analysis

This subject begins with a simple but decisive idea: before asking whether an argument is strong, first ask what kind of passage you are dealing with. A claim asserts something that can in principle be true or false; a question requests information; an explanation tries to show why an assumed event occurred; an argument offers one or more reasons in support of a conclusion. The same word, such as “because,” can appear in an explanation or an argument, so signal words alone are not enough. Context and function matter: is the conclusion being established, or is an accepted event being explained?

Once the passage is identified as an argument, reconstruct it before evaluating it. Write the conclusion the author wants you to accept, then the premises offered, then the smallest relevant unstated assumption needed to connect them. Do not invent motives or preferences that the reasoning does not need, and do not call every missing fact an “assumption.” The cost of a decision or the availability of a room may be application information to gather later, while an assumption is an inferential bridge. Mapping the argument also helps you see whether premises work together as linked support or offer separate independent reasons.

Linguistic clarity is not merely stylistic. Reasoning can change completely when a key term changes meaning. If “light” means low complexity in one premise and low physical weight in another, the argument fails to preserve the same term. Definitions help stabilize meaning. An operational definition can specify how the team will measure “high congestion,” but it does not prove that congestion occurred or that the selected threshold is universal. Always separate defining the criterion from measuring reality.

Necessary and sufficient conditions are another common source of reversal. If A is necessary for B, then whenever B occurs, A must be present. If A is sufficient for B, then A guarantees B under the stated rule. Being on an entry list may be necessary but not sufficient for express entry if a valid code is also required. Conversely, saying a condition is sufficient does not make it the only route to the outcome unless the rule states that as well.

After reconstruction and clarification, evaluate the argument on three axes. First, premise acceptability: What is the source? How was a fact measured? Is it a one-off impression or adequate evidence? Second, relevance: a supplier’s age may be true but still fail to establish the technical capability required by a contract. Third, inferential support: even true and relevant premises can support a conclusion that is too broad. Three of five users preferring one design does not justify saying that all users will prefer it.

Separating these axes prevents recurring errors. A true conclusion does not automatically make the reasoning good; a conclusion can be true while the offered reasons are irrelevant. Conversely, a false premise does not stop us from inspecting the inferential structure. We can provisionally assume the premises and ask whether the conclusion follows. In valid deduction, true premises cannot coexist with a false conclusion; when the premises are also true, the argument is sound. Nondeductive arguments generally require judging degrees of support rather than a complete guarantee, a distinction developed in later subjects.

Use this practical sequence whenever you read a passage: identify its function; if it is an argument, extract conclusion and premises; state an unstated assumption only when it is needed for the inferential bridge; stabilize the meaning of key terms; check necessary and sufficient conditions in the correct direction; then evaluate premise acceptability, relevance, and the strength of support. This sequence turns critical thinking from a quick reaction into a process that can be explained, reviewed, and improved.

Review questions

Test your understanding with these questions. Marking and saved results are available with a free account.

Question 1“A second staff member should be added because the queue exceeded ten minutes.” What is the main function of the passage? A question requesting information. A single claim asserting a fact. An explanation of an assumed fact. An argument offering a reason for a recommendation.
Question 2Which option is a question rather than a claim? The room seats eighty people. Waiting time fell today. How long was the wait? The session began at nine.
Question 3The sentence says, “The session started late because the projector had to be restarted,” and the delay itself is agreed. What is the best classification? A question. An explanation. An argument proving that the session was late. An operational definition.
Question 4Which change turns the explanation “Noise fell because the door was closed” into an argument whose goal is to establish that the door was closed? Add a sensor log and time-stamped image as evidence that the door was closed. Repeat “the door was closed” twice. Replace “because” with “therefore” only. Describe the noise as very annoying.
Question 5In “Let us use Room B; it seats 80 people and registration is 62,” what is the conclusion? Room B seats 80. Current registration is 62. Room B should be used. Every room seating 80 is always suitable.
Question 6What is the best unstated assumption for the room argument? Participants prefer the color blue. If capacity exceeds expected attendance and no decisive constraint exists, the room is suitable in terms of capacity. Every registered person will definitely attend. Room B is cheaper than every other room.
Question 7In “The evening course should continue; thirty learners registered,” which option is most clearly missing information rather than a logical assumption? Registration can indicate demand to some degree. Continuing the course is a decision that needs a reason. Thirty is greater than zero. The cost of running the evening course compared with its revenue or benefit.
Question 8Which description matches linked support? Two premises need to work together for the intended part of the inference to succeed. Two premises use identical wording. Two reasons are each unrelated to the conclusion. Two conclusions have no premises.
Question 9In “The plan is light; everything light is easy to carry; therefore the plan is easy to carry,” what is the central problem? The first premise is a question rather than a claim. The word “light” shifts from low complexity to low physical weight. The conclusion is an operational definition. No word is repeated.
Question 10A team defines “high congestion” as more than 20 people in the queue for ten continuous minutes. What does the definition establish by itself? Twenty is the globally optimal threshold. High congestion occurred today. How the team will classify cases as high congestion. Every queue of nineteen people is comfortable.
Question 11If being on today’s list is necessary for entry, which statement follows? If a person enters, their name must be on the list. If a name is on the list, entry is guaranteed. Everyone on the list has an access code. Entry is necessary for being on the list.
Question 12The rule states, “A certificate is sent only to learners who completed the units and passed the assessment.” What cannot be inferred from this sentence alone? If a certificate was sent, the units were completed. If a certificate was sent, the learner passed the assessment. Completion and passing are necessary conditions for sending. Completion and passing together guarantee sending with no other condition.
Question 13Which statement correctly separates premise truth from inferential quality? If the conclusion is true, the argument must be good. If one premise is false, the logical structure cannot be evaluated. Premise truth and whether premises support the conclusion can be tested as different questions. Logic never cares about premises.
Question 14“The supplier was founded twenty years ago, therefore it is best for a contract requiring a specific technical capability.” What is the clearest defect? There is no conclusion. The premise may be true, but it does not establish the required technical capability. Long history makes the conclusion certain. The premise is an operational definition.
Question 15“Three of five users preferred design A, therefore all users will prefer it.” What is the best correction? Delete the sample data and keep “all.” Add the word “definitely” before the conclusion. Replace 3 of 5 with 3 of 4 without collecting new data. Narrow the conclusion to “in this small sample, three of five preferred A,” or collect broader evidence before generalizing.
Question 16Assume both premises are true: “Everyone who attended the training passed” and “Sara attended the training.” How should the move to “Sara passed” be evaluated? The deductive transition is valid under the assumed premises. The conclusion is unrelated to the premises. The transition cannot be evaluated until we know attendance numbers. The argument is weak because the conclusion concerns one person.