Watson-Glaser Critical Thinking Appraisal Inferences 5 — Questions and Answers
Question 1: Passage: A survey of 500 adults found that those who read for at least 30 minutes daily reported lower stress levels. A wellness coach concludes: 'Reading daily reduces stress.' This inference is: A) True — the survey proves reading reduces stress. B) Probably true — there is a consistent association between reading and lower stress. C) Insufficient data — people with lower stress may simply have more time to read. D) False — reading has no effect on stress.
- True — the survey proves reading reduces stress.
- Probably true — there is a consistent association between reading and lower stress.
- Insufficient data — people with lower stress may simply have more time to read. (Correct answer)
- False — reading has no effect on stress.
Correct answer: Insufficient data — people with lower stress may simply have more time to read.
Reverse causation is equally plausible — people who are less stressed may have more leisure time for reading — so the survey alone cannot establish direction of cause.
Question 2: Statement: In Greenfield County, vehicle accident rates are highest on Fridays between 5 PM and 8 PM. A traffic official infers that rush hour fatigue on Fridays is the primary cause. This inference is: A) Probably true — fatigue combined with end-of-week traffic is a plausible primary cause. B) Certainly true — the peak time clearly shows fatigue is the cause. C) Insufficient data — alcohol use and increased traffic volume on Friday evenings are unexamined factors. D) False — accidents are always caused by poor road conditions.
- Probably true — fatigue combined with end-of-week traffic is a plausible primary cause.
- Certainly true — the peak time clearly shows fatigue is the cause.
- Insufficient data — alcohol use and increased traffic volume on Friday evenings are unexamined factors. (Correct answer)
- False — accidents are always caused by poor road conditions.
Correct answer: Insufficient data — alcohol use and increased traffic volume on Friday evenings are unexamined factors.
Friday evening accidents could also be driven by increased alcohol consumption, higher traffic density, or reduced daylight — these alternatives must be examined before attributing primacy to fatigue.
Question 3: A product recall was issued for a children's toy after three injury reports out of two million units sold. A parent concludes the toy is extremely dangerous. This inference is: A) Probably true — any injuries prove the toy is dangerous. B) Certainly true — a recall always means extreme danger. C) Probably false — three injuries in two million units suggests a very low injury rate. D) Insufficient data — more information on injury severity is needed.
- Probably true — any injuries prove the toy is dangerous.
- Certainly true — a recall always means extreme danger.
- Probably false — three injuries in two million units suggests a very low injury rate. (Correct answer)
- Insufficient data — more information on injury severity is needed.
Correct answer: Probably false — three injuries in two million units suggests a very low injury rate.
An injury rate of 0.00015% is extremely low; characterizing the toy as 'extremely dangerous' is not supported by the data.
Question 4: Passage: In a debate class, students who spoke last in each round won 65% of judges' decisions. The teacher infers that speaking last gives a competitive advantage. This inference is: A) Probably true — recency effect in memory can favor the last speaker. B) Certainly true — 65% is a definitive majority that proves an advantage. C) Insufficient data — stronger debaters may systematically choose or be assigned the last speaking slot. D) False — speaking order never affects judging outcomes.
- Probably true — recency effect in memory can favor the last speaker.
- Certainly true — 65% is a definitive majority that proves an advantage.
- Insufficient data — stronger debaters may systematically choose or be assigned the last speaking slot. (Correct answer)
- False — speaking order never affects judging outcomes.
Correct answer: Insufficient data — stronger debaters may systematically choose or be assigned the last speaking slot.
If more skilled debaters tend to speak last (by choice or assignment), the win rate would reflect skill rather than speaking order, making the causal inference unjustified.
Question 5: Statement: Only licensed electricians are permitted to perform wiring inspections in Bayside. Kevin performed a wiring inspection in Bayside. What is the most justified inference? A) Kevin is probably a licensed electrician. B) Kevin is definitely a licensed electrician. C) Kevin performed the inspection illegally. D) Kevin recently obtained his electrician's license.
- Kevin is probably a licensed electrician.
- Kevin is definitely a licensed electrician. (Correct answer)
- Kevin performed the inspection illegally.
- Kevin recently obtained his electrician's license.
Correct answer: Kevin is definitely a licensed electrician.
Since only licensed electricians are permitted to perform inspections and Kevin performed one, he must be a licensed electrician — this follows with certainty from the stated rule.
Question 6: A company's customer satisfaction scores dropped from 88% to 79% in the quarter following a switch to a new customer service software platform. The CTO infers the software caused the satisfaction drop. This inference is: A) Probably true — the timing of the software switch aligns with the score decline. B) Certainly true — the correlation is too strong to be coincidental. C) Insufficient data — staff training gaps, seasonal changes, or product issues could also explain the drop. D) False — software changes never affect customer satisfaction.
- Probably true — the timing of the software switch aligns with the score decline. (Correct answer)
- Certainly true — the correlation is too strong to be coincidental.
- Insufficient data — staff training gaps, seasonal changes, or product issues could also explain the drop.
- False — software changes never affect customer satisfaction.
Correct answer: Probably true — the timing of the software switch aligns with the score decline.
The close temporal link between the software switch and the satisfaction drop makes it probable (though not certain) that the new platform contributed to the decline.
Question 7: Passage: A political candidate who spent the most money on advertising won 80% of the elections studied over a 10-year period. A campaign manager infers that outspending opponents guarantees election victory. The word 'guarantees' makes this inference: A) Valid — 80% is close enough to certainty. B) Invalid — 80% success still means 20% failure, so victory is not guaranteed. C) Probably true — spending more money is the best predictor of winning. D) Insufficient data — we need to know the sample size.
- Valid — 80% is close enough to certainty.
- Invalid — 80% success still means 20% failure, so victory is not guaranteed. (Correct answer)
- Probably true — spending more money is the best predictor of winning.
- Insufficient data — we need to know the sample size.
Correct answer: Invalid — 80% success still means 20% failure, so victory is not guaranteed.
An 80% rate is strong evidence of an association, but 'guarantees' requires 100% certainty — a 20% failure rate directly contradicts any claim of a guarantee.
Watson-Glaser Critical Thinking Appraisal Inferences 5
Passage: A survey of 500 adults found that those who read for at least 30 minutes daily reported lower stress levels.
A wellness coach concludes: 'Reading daily reduces stress.' This inference is:
A) True — the survey proves reading reduces stress.
B) Probably true — there is a consistent association between reading and lower stress.
C) Insufficient data — people with lower stress may simply have more time to read.
D) False — reading has no effect on stress.