Watson-Glaser Critical Thinking Appraisal Inferences 3 — Questions and Answers
Question 1: A school district replaced textbooks with tablets. Reading scores among elementary students rose 10% the following year. The superintendent concludes tablets improved reading scores. This inference is: A) True — the data directly proves it. B) Probably true — the change is the most obvious cause. C) Insufficient data — other simultaneous changes could explain the gain. D) False — tablets never help with reading.
- True — the data directly proves it.
- Probably true — the change is the most obvious cause.
- Insufficient data — other simultaneous changes could explain the gain. (Correct answer)
- False — tablets never help with reading.
Correct answer: Insufficient data — other simultaneous changes could explain the gain.
Without a control group or knowledge of other variables (new teachers, curriculum changes, demographics), the causal link cannot be established from this data alone.
Question 2: In a study, people who ate breakfast daily were 25% less likely to be overweight. A nutritionist infers: 'Skipping breakfast causes weight gain.' This inference is: A) Probably true — the study directly shows causation. B) Insufficient data — the association does not prove breakfast skipping causes weight gain. C) True — all studies show the same result. D) False — breakfast has no effect on weight.
- Probably true — the study directly shows causation.
- Insufficient data — the association does not prove breakfast skipping causes weight gain. (Correct answer)
- True — all studies show the same result.
- False — breakfast has no effect on weight.
Correct answer: Insufficient data — the association does not prove breakfast skipping causes weight gain.
An observational association between eating habits and weight cannot establish that skipping breakfast directly causes weight gain; reverse causation or confounders are possible.
Question 3: Passage: Riverdale's public library saw a 35% increase in visitors after extending its hours. The mayor claims the extended hours are responsible. What additional information would most strengthen this inference? A) The library also purchased new books during that period. B) Visitor counts at other city libraries without extended hours remained flat. C) The library hired additional staff when hours were extended. D) Library funding increased the same year.
- The library also purchased new books during that period.
- Visitor counts at other city libraries without extended hours remained flat. (Correct answer)
- The library hired additional staff when hours were extended.
- Library funding increased the same year.
Correct answer: Visitor counts at other city libraries without extended hours remained flat.
Showing that comparable libraries without the hour extension did not see a visitor increase isolates extended hours as the likely cause.
Question 4: All mammals are warm-blooded. Whales are mammals. Therefore, which of the following inferences is definitely true? A) Whales breathe air because they are mammals. B) Whales are warm-blooded. C) All warm-blooded animals are mammals. D) Whales live longer than other warm-blooded animals.
- Whales breathe air because they are mammals.
- Whales are warm-blooded. (Correct answer)
- All warm-blooded animals are mammals.
- Whales live longer than other warm-blooded animals.
Correct answer: Whales are warm-blooded.
Since all mammals are warm-blooded and whales are mammals, it is definitively true that whales are warm-blooded.
Question 5: A company's Q3 profits rose 18% while competitor profits fell 5%. The CEO infers the company's new marketing strategy, launched at the start of Q3, is responsible. This inference is best described as: A) Certainly true — competitors' losses confirm the strategy worked. B) Probably true — the company outperformed competitors after the launch. C) Insufficient data — market conditions or other factors may explain both trends. D) Certainly false — marketing rarely affects profits.
- Certainly true — competitors' losses confirm the strategy worked.
- Probably true — the company outperformed competitors after the launch. (Correct answer)
- Insufficient data — market conditions or other factors may explain both trends.
- Certainly false — marketing rarely affects profits.
Correct answer: Probably true — the company outperformed competitors after the launch.
Outperforming competitors after the strategy launch is reasonably consistent with the strategy being effective, making this a probable — though not certain — inference.
Question 6: Passage: In the past decade, coffee consumption in the US has increased by 20%, and rates of type 2 diabetes have declined by 8%. A researcher concludes that coffee protects against diabetes. This is an example of: A) A valid causal inference supported by the data. B) A probable inference because the trends align. C) An unjustified causal inference from correlational data. D) A false inference because coffee is harmful.
- A valid causal inference supported by the data.
- A probable inference because the trends align.
- An unjustified causal inference from correlational data. (Correct answer)
- A false inference because coffee is harmful.
Correct answer: An unjustified causal inference from correlational data.
Two simultaneous population trends do not establish a causal link; many unrelated factors changed over the same decade.
Question 7: Every employee promoted to manager in the last five years had at least one year of project-lead experience. David has two years of project-lead experience. What can be inferred about David? A) David will be promoted to manager. B) David meets one criterion that all recent manager promotions shared. C) David is the most qualified candidate for promotion. D) David will definitely not be promoted without additional qualifications.
- David will be promoted to manager.
- David meets one criterion that all recent manager promotions shared. (Correct answer)
- David is the most qualified candidate for promotion.
- David will definitely not be promoted without additional qualifications.
Correct answer: David meets one criterion that all recent manager promotions shared.
The passage establishes that project-lead experience was present in every promotion, so David satisfies that shared characteristic — nothing more can be concluded.
Watson-Glaser Critical Thinking Appraisal Inferences 3
A school district replaced textbooks with tablets.
Reading scores among elementary students rose 10% the following year.
The superintendent concludes tablets improved reading scores.
This inference is:
A) True — the data directly proves it.
B) Probably true — the change is the most obvious cause.
C) Insufficient data — other simultaneous changes could explain the gain.
D) False — tablets never help with reading.