Attention as a finite resource: protecting it, spending it, and recovering it. For additional background on this subject, consult the attention-management overview. For a practical software example related to productivity versus efficiency, read the full guide.
Cal Newport's term names a specific kind of cognitive effort, distinguishes it from busyness, and argues it's becoming both rarer and more valuable.
Not a call to quit technology, but a specific method for deciding which tools are worth their cost in attention.
Doing two things 'at once' almost always means switching rapidly between them — and the switch itself has a measurable cost most people underestimate.
Mihaly Csikszentmihalyi's concept of flow has specific, testable preconditions — it isn't a mood you can simply decide to have.
Doing one thing at a time sounds obvious until you notice how many small habits quietly work against it.
Switching tasks doesn't fully clear the previous one from working memory. That leftover attention has a name and a measurable cost.
A focus block that only works in ideal conditions doesn't work at all. The design has to account for the interruptions it will actually face.
A quick check feels free. The research on attention residue and switching cost suggests it almost never is.
Downtime is usually treated as the opposite of productive time. The research on cognitive recovery treats it as a required input.