What is unfinished task focus?

Unfinished task focus is a concept in personal epistemology: Unfinished tasks leave attention residue that degrades focus on subsequent tasks.

Example: You're writing a proposal when a Slack message pulls you into a hiring discussion. You reply, then return to the proposal — but for the next fifteen minutes your sentences are vague, your reasoning shallow. You're physically back on the proposal, but a piece of your mind is still weighing whether that candidate is worth a second interview. That piece is attention residue, and it is consuming working memory slots you need for the task in front of you.

This concept is part of Phase 4 (Attention and Focus) in the How to Think curriculum, which builds the epistemic infrastructure for attention and focus.