Full Idea
Slogan for disjunctivism: perceptual knowledge is paradigmatically constituted by a true belief whose epistemic support is both factive (i.e. it entails the truth of the propositions believed) and reflectively accessible to the agent.
Gist of Idea
Disjunctivism says perceptual justification must be both factual and known by the agent
Source
Duncan Pritchard (Epistemological Disjunctivism [2012], Intro)
Book Reference
Pritchard,Duncan: 'Epistemological Disjunctivism' [OUP 2012], p.3
A Reaction
I'm not a fan of externalism, but it could be that the factive bit achieves the knowledge, and then being able to use and answer for that knowledge may just be a bonus, and not an essential ingredient.