STAT Argument and Evidence Analysis 3 — Questions and Answers
Question 1: A newspaper editorial states: 'Teen crime rates fell after the youth curfew was introduced; therefore, the curfew caused the reduction.' Which flaw does this reasoning contain?
- False analogy
- Post hoc ergo propter hoc (Correct answer)
- Appeal to authority
- Circular reasoning
Correct answer: Post hoc ergo propter hoc
Assuming that because B followed A, A caused B is the post hoc fallacy — correlation in time does not establish causation.
Question 2: An argument uses the following structure: 'All mammals are warm-blooded. Dolphins are warm-blooded. Therefore, dolphins are mammals.' This reasoning is:
- Valid deductive reasoning
- An example of affirming the consequent (Correct answer)
- Sound because the conclusion is true
- Inductive reasoning from a sample
Correct answer: An example of affirming the consequent
This is affirming the consequent: just because dolphins share one property of mammals does not logically guarantee they are mammals.
Question 3: In evaluating a scientific study as evidence, which factor is most important for assessing its reliability?
- The study was published in a widely-read magazine.
- The findings confirm widely-held beliefs.
- The study was peer-reviewed and used a large sample size. (Correct answer)
- The lead researcher is a well-known expert.
Correct answer: The study was peer-reviewed and used a large sample size.
Peer review and large sample sizes are key methodological markers of a reliable study.
Question 4: A health advertisement claims: '9 out of 10 dentists recommend our toothpaste.' Which question is most critical for evaluating this claim?
- What country was the advertisement produced in?
- How many dentists were surveyed and how were they selected? (Correct answer)
- What flavor of toothpaste was tested?
- When was the toothpaste formula last changed?
Correct answer: How many dentists were surveyed and how were they selected?
Without knowing the sample size and selection method, the statistic cannot be evaluated for representativeness or bias.
Question 5: Which of the following is an example of anecdotal evidence being used to support a general claim?
- A clinical trial found the drug reduced symptoms in 70% of patients.
- Government statistics show crime fell 5% last year.
- 'My grandfather smoked his whole life and lived to 95, so smoking can't be that harmful.' (Correct answer)
- A meta-analysis of 50 studies concluded exercise reduces dementia risk.
Correct answer: 'My grandfather smoked his whole life and lived to 95, so smoking can't be that harmful.'
Using one person's experience to draw a general conclusion about population-level risk ignores statistical evidence.
Question 6: A policy paper argues that mandatory voting should be introduced because 'citizens have a duty to participate in democracy.' What type of premise is this?
- An empirical claim backed by data
- A normative claim based on a value judgment (Correct answer)
- A causal hypothesis requiring testing
- An operational definition of democracy
Correct answer: A normative claim based on a value judgment
The claim that citizens 'have a duty' is a value judgment about what ought to be, not a factual statement about what is.
Question 7: A lawyer argues: 'My client is innocent because the prosecution has not proven guilt beyond reasonable doubt.' Which logical principle does this illustrate?
- The burden of proof lies with the one making the positive claim. (Correct answer)
- Innocence is established by character witnesses.
- Reasonable doubt is always present in legal cases.
- Defense attorneys never need to present evidence.
Correct answer: The burden of proof lies with the one making the positive claim.
In legal reasoning, the burden of proof falls on the prosecution; failure to meet that burden justifies acquittal.
STAT Argument and Evidence Analysis 3
A newspaper editorial states: 'Teen crime rates fell after the youth curfew was introduced; therefore, the curfew caused the reduction.' Which flaw does this reasoning contain?