Assumption Questions: The Negation Test
Assumption questions present an argument and ask: 'The argument above assumes which of the following?' The correct answer is a statement that the argument requires to be true — a gap-filling claim that is not stated in the argument but is logically necessary for the conclusion to follow from the evidence. The wrong answers include statements that are true or plausible but that the argument does not logically require.
The most reliable technique for Assumption questions is the Negation Test: for each answer choice, negate it (assume it is false) and check whether the negation destroys the argument. If negating the answer choice makes the argument fall apart — the conclusion can no longer be drawn from the evidence — that answer choice is the assumption the argument requires. If negating the answer choice leaves the argument unaffected, it is not a necessary assumption.
Example argument: 'Our sales team has received more customer training hours than any competitor's sales team. Therefore, our customers are more satisfied than competitor customers.' This argument requires bridging assumptions. Apply the Negation Test to candidate answer: 'Training hours are related to customer satisfaction.' Negating this: 'Training hours are not related to customer satisfaction.' If training hours are unrelated to satisfaction, the entire argument collapses — more training hours would give no reason to expect more satisfaction. This statement is a necessary assumption. Contrast with: 'Our sales team has better morale than competitor teams.' Negating this: 'Our sales team does not have better morale.' This negation doesn't destroy the argument (it could still be true that training hours drive satisfaction regardless of morale). Not a necessary assumption.
The four types of assumptions most common on GMAT: (1) Source-to-Conclusion Bridging: the evidence concerns one domain (training hours) and the conclusion concerns another (satisfaction) — the assumption connects them. (2) No-Alternative Explanation: the argument assumes no other factor could explain the outcome. (3) Applicability: the argument assumes conditions in a cited study/example apply to the current situation. (4) Feasibility: the argument assumes a proposed action is actually possible or that no obstacle prevents it.