Attention is not engagement. Dwell time is.

distinction — attributed to James Lancaster

A packed room means little if the audience mentally checks out five minutes into a session. In journalism the real measure of engagement is dwell time — how long someone stays with a story before moving on. The same principle applies to gatherings. People stay with complex material when the substance rewards their attention. Hooks are easy. Holding is hard.

Lancaster's warning that the industry has begun confusing the two.

engagement, attention, dwell-time, retention, program-design