Watson-Glaser Critical Thinking Appraisal Evaluating Causal Relationships 4

Question 1

A city installs more streetlights in high-crime neighborhoods, and crime drops by 20% over the next year. A resident concludes that the streetlights caused the crime reduction. Which alternative explanation most weakens this causal claim?

Accepted Answer

The city also increased police patrols in those neighborhoods during the same period.

Answer

A concurrent intervention (increased patrols) is a confounding variable that could independently explain the crime reduction, undermining the streetlight-as-cause claim.

Question 2

Which of the following best describes the logical fallacy 'post hoc ergo propter hoc'?

Accepted Answer

Assuming that because one event followed another, the first caused the second.

Answer

'Post hoc ergo propter hoc' means 'after this, therefore because of this'—incorrectly inferring causation from temporal sequence alone.

Question 3

Researchers find that people who eat breakfast regularly have higher academic performance. A school mandates breakfast for all students. Which assumption is necessary for this policy to achieve its goal?

Accepted Answer

The correlation between breakfast and performance reflects a causal relationship.

Answer

The policy only works if eating breakfast actually causes better performance, not merely if it correlates with it (e.g., via a third factor like household stability).

Question 4

A study shows that hospitals with more nurses per patient have lower patient mortality rates. An administrator concludes: 'Hiring more nurses will reduce deaths.' What is the strongest challenge to this conclusion?

Accepted Answer

Better-funded hospitals may both hire more nurses and have other quality advantages that reduce mortality.

Answer

Reverse causation or a shared underlying cause (hospital funding/quality) could explain the correlation without nurse staffing being the direct cause.

Question 5

In Watson-Glaser reasoning, which of the following scenarios demonstrates a 'necessary cause' rather than a 'sufficient cause'?

Accepted Answer

Oxygen must be present for a fire to burn, but oxygen alone does not start a fire.

Answer

A necessary cause must be present for the effect to occur but does not guarantee it; oxygen is required for fire but alone cannot produce it.

Watson-Glaser Critical Thinking Appraisal Practice Test

Watson-Glaser Critical Thinking Appraisal Practice Test

Watson-Glaser Critical Thinking Appraisal Evaluating Causal Relationships 4