Time boxing in this case is about something different. It is for making conscious decision on choosing what and what not to talk about during the conversation. It is more for eliminating than for being in a rush.
In order to have effective timeboxed meeting as a facilitator:
- ensure everybody agrees what is the goal of the meeting, what is expected outcome and what decisions should be made (eg. planning meeting - we want to have items discussed with defined acceptance criteria, estimated and have brush design),
- ensure that agenda (structured) is agreed,
- keep an eye on time,
- if time is in danger, say it aloud and remind the goal, expected outcome and decision,
- ask what participants think they should focus on or eliminate in order to get the results in the timebox,
- if time is about to exceed the timebox, make an agreement for another time box (eg. we exceed the meeting for 30 minutes),
- sum up the results,
- sometimes it may be useful to make a short retrospective afterwards to find ways to improve the meeting.