Watson-Glaser Critical Thinking Appraisal Interpreting Evidence and Data 3 — Questions and Answers
Question 1: A pie chart shows that Department X uses 45% of the company's budget. A colleague concludes that Department X is wasteful. What is wrong with this conclusion?
- Pie charts cannot show budget data
- Budget share alone does not indicate waste or efficiency (Correct answer)
- 45% is always too high for any department
- The chart proves Department X is the most important
Correct answer: Budget share alone does not indicate waste or efficiency
A large budget share may reflect the department's size or workload, not wasteful spending.
Question 2: A clinical trial reports a drug reduces symptom duration by 2 days (p < 0.01). Which statement best interprets this finding?
- The drug cures the disease
- The result is statistically significant but may not be clinically meaningful (Correct answer)
- p < 0.01 means the drug works for 99% of patients
- Statistical significance guarantees large practical benefit
Correct answer: The result is statistically significant but may not be clinically meaningful
Statistical significance indicates the result is unlikely due to chance, but a 2-day reduction may or may not matter clinically.
Question 3: Data shows that ice cream sales and drowning rates both peak in summer. The best interpretation is:
- Ice cream consumption causes drowning
- Both variables share a common cause—hot weather and increased outdoor activity (Correct answer)
- Drowning causes people to buy more ice cream
- Summer data is always unreliable
Correct answer: Both variables share a common cause—hot weather and increased outdoor activity
A lurking variable (summer heat and outdoor activity) drives both trends, making direct causation between them implausible.
Question 4: A scatter plot shows a strong positive correlation (r = 0.92) between hours of TV watched and test scores. What is the most accurate interpretation?
- Watching TV strongly improves test scores
- There is a strong association, but the direction of causation is unclear (Correct answer)
- r = 0.92 means 92% of students watch TV
- High TV consumption guarantees high test scores
Correct answer: There is a strong association, but the direction of causation is unclear
A high correlation coefficient indicates a strong relationship but does not reveal which variable, if either, causes the other.
Question 5: A news headline reads: 'New Study: People Who Exercise Live Longer.' The study was observational with no control group. The headline is best described as:
- Accurate because observational studies are definitive
- Overstated because the study cannot prove causation (Correct answer)
- Misleading because exercise has no health benefits
- Correct only if the sample size exceeded 1,000
Correct answer: Overstated because the study cannot prove causation
Without a control group, the study can only show association, not establish that exercise causes longer life.
Question 6: A table shows that Region A has a 5% unemployment rate and Region B has a 9% rate. Which factor would most complicate comparing these figures?
- The regions having different names
- Differences in how each region defines and measures unemployment (Correct answer)
- Region A having more cities than Region B
- The figures being published in different fonts
Correct answer: Differences in how each region defines and measures unemployment
If unemployment is measured differently (e.g., who counts as seeking work), the rates are not directly comparable.
Question 7: A researcher notices that as shoe size increases, reading ability also increases in a sample of children aged 3–12. The most reasonable explanation is:
- Larger feet help children read better
- Age is a confounding variable driving both shoe size and reading ability (Correct answer)
- The sample must be biased toward older children
- Reading practice causes feet to grow
Correct answer: Age is a confounding variable driving both shoe size and reading ability
Older children have both bigger feet and better reading skills, so age is the underlying confounding variable.
Watson-Glaser Critical Thinking Appraisal Interpreting Evidence and Data 3
A pie chart shows that Department X uses 45% of the company's budget.
A colleague concludes that Department X is wasteful.
What is wrong with this conclusion?