CCTST Deductive and Inductive 2 — Questions and Answers
Question 1: A researcher observes that every swan she has ever seen is white and concludes 'All swans are white.' What type of reasoning is this?
- Deductive reasoning
- Inductive reasoning (Correct answer)
- Abductive reasoning
- Analogical reasoning
Correct answer: Inductive reasoning
This is inductive reasoning because the conclusion generalizes beyond the observed cases to all swans.
Question 2: Which of the following is a valid deductive argument form?
- If P then Q; Q is true; therefore P is true
- If P then Q; P is true; therefore Q is true (Correct answer)
- P is usually followed by Q; P occurred; therefore Q will occur
- P and Q often co-occur; P is present; therefore Q caused P
Correct answer: If P then Q; P is true; therefore Q is true
Modus ponens (If P then Q; P is true; therefore Q is true) is a valid deductive argument form that guarantees the conclusion.
Question 3: A detective reasons: 'The crime occurred between 8 and 10 PM. Mr. Smith has a verified alibi for that entire period. Therefore, Mr. Smith did not commit the crime.' This is:
- Inductive reasoning because it involves uncertainty
- Invalid reasoning because alibis can be faked
- Valid deductive reasoning from established premises (Correct answer)
- Analogical reasoning based on similar cases
Correct answer: Valid deductive reasoning from established premises
Given the premises are true, the conclusion follows necessarily — this is valid deductive reasoning.
Question 4: Which feature BEST distinguishes a strong inductive argument from a weak one?
- The conclusion is logically impossible to deny
- The premises guarantee the truth of the conclusion
- The evidence makes the conclusion highly probable (Correct answer)
- The argument uses more than three premises
Correct answer: The evidence makes the conclusion highly probable
A strong inductive argument provides evidence that makes the conclusion highly probable, not certain.
Question 5: Consider: 'No mammals are cold-blooded. All dolphins are mammals. Therefore, no dolphins are cold-blooded.' This argument is:
- Valid and sound if premises are true (Correct answer)
- Invalid because the conclusion is too broad
- Inductive because it involves biological categories
- Valid but unsound because dolphins are fish
Correct answer: Valid and sound if premises are true
The argument is valid (conclusion follows necessarily from premises) and sound (both premises are true).
Question 6: Which scenario demonstrates the fallacy of affirming the consequent?
- If it rains, the ground gets wet. It rained. Therefore the ground is wet.
- If it rains, the ground gets wet. The ground is wet. Therefore it rained. (Correct answer)
- If it rains, the ground gets wet. It did not rain. Therefore the ground is not wet.
- It usually rains in April. It is April. Therefore it will rain today.
Correct answer: If it rains, the ground gets wet. The ground is wet. Therefore it rained.
Affirming the consequent incorrectly assumes that because Q is true, P must be true in an 'If P then Q' structure.
Question 7: An inductive generalization is considered cogent when:
- Its premises are true and the argument is strong (Correct answer)
- Its conclusion is logically guaranteed by the premises
- It uses a deductively valid argument form
- The sample size is exactly 100 or more
Correct answer: Its premises are true and the argument is strong
A cogent inductive argument is both strong (makes the conclusion probable) and has true premises.
CCTST Deductive and Inductive 2
A researcher observes that every swan she has ever seen is white and concludes 'All swans are white.' What type of reasoning is this?