Full Idea
Fluent speakers typically become increasingly hesitant about 'knowledge' attributions as the practical significance of the right answer increases.
Gist of Idea
People begin to doubt whether they 'know' when the answer becomes more significant
Source
Earl Conee (Contextualism Contested (and reply) [2005], 'Epistemic')
Book Reference
'Contemporary Debates in Epistemology (2nd ed)', ed/tr. Steup/Turri/Sosa [Wiley Blackwell 2014], p.65
A Reaction
The standard examples of this phenomenon are in criminal investigations, and in philosophical discussions of scepticism. Simple observations I take to have maximum unshakable confidence, except in extreme global scepticism contexts.