Assumption Questions — Revision Notes

⚡ 30-Second Revision

Revision checked 17 October 2026.

Find the premise-to-conclusion gap.
Necessary does not mean sufficient.
Negate all as at least one not.
Test the offered reasoning, not unrelated possibilities.
A helpful extra is not automatically required.

2-Minute Revision

For a necessary assumption, denial must damage the argument’s support. An online-only replacement promising access to every current user needs an effective route for every user; it does not need every user to own the latest device. Sample-based claims need a justified move from the observed group to the claimed population. Write that move explicitly before examining options.

5-Minute Revision

Original drill: A committee proposes a ferry in place of a footbridge and claims that residents will retain their existing early-morning access. Candidate assumptions: the ferry can operate at the relevant times; the ferry is painted blue; every resident prefers boats.

Denying the first directly damages the promised mechanism. Denying the other two need not. Now alter the conclusion to “the replacement is cheaper”. The relevant assumptions change because operating cost, capital cost and the comparison period now matter.

An assumption is tied to a specific conclusion.

Vyyuha Quick Recall

GAP: Get the conclusion; Articulate the missing link; Probe its denial. These are the three steps of the necessary-assumption test.