Critical Thinking & Reasoning Flashcards

A survey conducted on a website that sells vitamins finds that 90% of respondents believe vitamins are essential for health. The main problem with this data is:

Answer: The sample is biased because visitors to that site likely already favor vitamins

Sampling bias occurs when the group surveyed does not represent the general population — vitamin website visitors are not a neutral sample.

Which of the following best describes a counterargument's purpose in a well-reasoned essay?

Answer: To acknowledge and then rebut opposing perspectives to strengthen the main argument

Addressing and refuting opposing views demonstrates thorough reasoning and makes the main argument more persuasive.

A speaker argues: 'Nine out of ten dentists recommend this toothpaste.' Which question is MOST critical to ask about this claim?

Answer: Which dentists were surveyed, how many were asked, and who conducted the study?

The methodology, sample selection, and funding source of the survey determine whether the statistic is meaningful.

An argument is valid if:

Answer: The conclusion must be true if the premises are true

Validity is a structural property: if the premises were true, the conclusion could not be false — regardless of whether premises actually are true.

Which scenario demonstrates inductive reasoning?

Answer: The sun has risen every morning for thousands of years, so it will likely rise tomorrow.

Inductive reasoning draws a probable conclusion from repeated observations, but the conclusion is not guaranteed.

A student writes: 'Everyone knows that social media is harmful to teenagers.' The primary weakness of this opening claim is:

Answer: It makes an unsupported appeal to popular opinion as evidence

Saying 'everyone knows' is an appeal to popular opinion (bandwagon) and substitutes consensus for actual evidence.

Two premises: 'If a student studies consistently, they will pass the exam.' 'Maria did not pass the exam.' What conclusion follows logically?

Answer: Maria did not study consistently

By modus tollens: if consistent study → pass, and Maria did not pass, then Maria did not study consistently.