Strengthen and Assumption questions are the most frequently tested CR types and require identifying the gap in the author's reasoning — the unstated bridge between premises and conclusion.

A) What an Assumption Is

An assumption is an unstated premise the argument requires to be true in order for the conclusion to follow. The author states premises and conclusion but leaves one crucial piece implicit — that is the assumption.

• Supporter assumption: provides the missing logical link. "All X are Y" + premise "This is an X" → assumption "This is an X" (when not stated). Without it, the conclusion doesn't follow.
• Defender assumption: rules out an alternative explanation or attack that would otherwise undermine the conclusion.

B) The Negation Test

To verify an assumption: logically negate the answer choice and check whether the conclusion falls apart. If negating the assumption destroys the argument, it IS the assumption. Apply only to your top 1–2 finalists — not all five choices.

Example: Conclusion = "Reading improves intelligence." Assumption candidate = "Intelligence is not already fixed before reading occurs." Negate: "Intelligence IS fixed before reading." → Reading cannot improve it → conclusion fails. This IS the assumption. ✓

C) Strengthen Questions

Strengthen answers provide additional evidence that supports the conclusion or plug a gap in the reasoning. They go beyond the assumption — they add active support.

• The answer does not need to prove the conclusion — just make it more likely.
• New information is explicitly allowed.
• Correct answers often address the same gap as the assumption but from a positive "supporting" angle.

D) Identifying the Question Types

• Assumption: "The argument depends on assuming," "conclusion requires which of the following," "relies on the assumption that"
• Strengthen: "Which of the following, if true, most strengthens," "supports," "helps justify," "provides the most support for"

E) The Five Trap Types

• Opposite: weakens instead of strengthening (very common in strengthen questions).
• Shell Game: looks like it supports the conclusion but actually supports a subtly different claim.
• Out of scope: new information that doesn't connect to the conclusion.
• Premise paraphrase: simply restates what was already said — not new support.
• Too extreme / primary cause: answer overstates the factor as "most important" or "only cause" — avoid overreaching answers.

F) Strategy

1. Identify the conclusion and premises.
2. Identify the reasoning gap: "The author goes from [premises] to [conclusion] by assuming [X]."
3. Pre-think the assumption or strengthener before reading choices.
4. For assumption: use the Negation Test on finalists. For strengthen: ask "does this make the conclusion more likely?"
5. Accept new information; reject any choice that weakens the conclusion.