Critical Reasoning: weakening vs flaw questions — how to tell apart?

✓ Accepted answer

Clear distinction: Weaken question: asks you to find information that, if true, reduces the strength of the conclusion. You're bringing something from outside — a new fact, a counterexample, an alternative explanation — that the argument didn't account for. The information isn't in the argument; it's external evidence. Flaw question: asks you to describe what is logically wrong with the argument itself — an error in reasoning that exists regardless of whether the premises are true. You're not introducing new information; you're identifying a structural defect. Common flaws: confusing correlation with causation, assuming the sample represents the population, treating a necessary condition as a sufficient one. How to tell them apart under time pressure: - Read the question stem first. 'Which of the following, if true...' → Weaken (external info). 'The argument is flawed because...' → Flaw (structural defect). - Flaw answer choices almost always start with 'assumes without justification that,' 'confuses,' 'fails to consider,' or 'treats X as if it were Y.' If an answer choice reads like a factual statement or introduces a new entity, it's not a flaw answer. A useful pre-solving habit: before looking at any answer choice, write one sentence — 'The argument assumes ___.' This pre-identifies the gap. A weaken answer attacks that assumption from outside; a flaw answer names that assumption as the structural error. This single habit eliminates most confusion between the two question types.