Recently I have been considering why real-time online education using video conferencing (called "synchronous online learning" by education theorists) works so poorly. The tools today seem little better than video conferencing from 15 years ago. While more bandwidth and more reliable links may help, I suggest that the technology is trying to solve the wrong problem, because a group discussion is not like a one on one conversation.
One thought was to accept that communication in a group of people, such as a class, is not like a one-to-one conversation. If we assumed that only one person can talk at a time (half-duplex) and only can say a little and then pause for a reply, that will make the technology easier and allow for more computer mediation.
A time limit of about 30 seconds, being the speaking equivalent of an SMS message, would seem reasonable. Breaking a conversation up into 30 second packets might seem very unnatural. But Twitter has been very successful, breaking text conversations up this way. While that makes the conversation less free-flowing, it adds many advantages.
But is 30 seconds a good length for an audio message? I started searching to see if there was any research on how long people talk for continuously in a conversation. After a couple of web searches I found there was a whole area of research devoted to the "length of utterance" and this is used to measure language proficiency.
The "turn length" for Small-group Discussions (Li & Nesi, 2004) discussions has been reported to be from 23.1 to 71.5 seconds. This suggests that the maximum length for an audio/video message needs to be longer than 30 seconds, perhaps 120 seconds.
Also interesting is that discussions between students finished after 5 minutes 49 seconds to 6 minutes 31 seconds. This is much shorter than the typical 30 or 60 minute business meeting or education class. Perhaps if we had a way to organize meetings and classes more easily, they could be of this more natural short length.
In addition the researchers noted differences in the structure of discussion between Chinese and English speakers. They also noted the frustration when the groups mixed and while they spoke the same language, they used different discussion techniques. Perhaps explicit cues could be built into the Computer Medicated Communications system, where something like emote-icons would indicate if the speaker was Reformulating a point, Endorsing, or so on. Also it may be useful to teach students about different discussion styles.
Li, M., & Nesi, H. (2004). Exchange Patterns in Small-group Discussions: a comparative study of Chinese and English discourse in peer group, divergent discussion tasks. The East Asian Learner, 1(2). Retrieved from: http://www.brookes.ac.uk/schools/education/eal/eal-1-2/vol1-no2-li-nesi.html