Effect of speed of writing, reading, talking and listening

Why the optimal group size is larger for text-based than for voice-based collaborative communication

Excerpt from the book Electronic Mail by Jacob Palme.

A fuller discussion of this topic is also available.

An interesting factor to note is that, in a face-to-face meeting with 5 participants, each participant is allowed to talk for an average of 20 percent of the time. In an electronic mail meeting with 33 participants, each participant also spends 20 percent of the time giving information, writing messages, etc. See the figure below.

Electronic mail discussion with 33 participants			Face-to-face meeting with five participants
	Typing: 3.6 minutes Reading: 32 x 0.47 = 15 minutes Total time: 18.6 minutes Typing for 3.6 of 18.6 minutes = 20 %			Speaking: 1.2 minutes Listening: 4x1.2 minutes = 4.8 minutes Total time: 6 minutes Speaking for 1.2 of 6.0 minutes = 20 %
Number of participants to get roughly 20 percent giving and 80 percent receiving per participant. This picture is also available in binhexed Macintosh PICT format.

Maybe human communication (with equal speaker rights) works best psychologically if the participants can be active and give information at least 20 percent of the time. This could be the reason why face-to-face meetings seem to be most efficient with group sizes of about 3-7 people, while group communication using electronic mail or computer conferencing systems seems to be efficient in groups of 20-100 people or more.

URL of this web page: http://dsv.su.se/jpalme/e-mail-book/meeting-comparison.html