- Threaded conferencing engines are shrubs.
- Linear conferencing engines are bamboo.
If you want direction and momentum, be bamboo.
Covering two factors in particular detail:
Attention
- Threaded conferencing dissipates attention. The longer the conversation goes on, the more spread out upon the branches twigs and leaves the community's attention becomes. Before long, people are spending more time navigating the tree trying to find something to respond to than they are actually responding.
Linear conferencing concentrates attention. The only place to contribute to a discussion is at the bottom, by which time you've hopefully read everything that has happened or at least the last few posts. Navigational overhead remains constant nomatter how long a discussion topic lasts. Compounding these tendencies is the difficulty in coding "last read" features in a threaded conferencing system -- there's just too much to keep track of, and even if you did the user will still have to click at least as many times as new leaves have sprouted from the branches. Implementing "last read" in a linear conferencing system is as easy as keeping a Dictionary storing the last read item by topic identifier. Catching up often requires only one click per topic.
Flamewars
- Threaded conferencing promotes flamewars. Users see provocative material and are offered a chance to respond to it before reviewing what anyone else has said. This tends to feed back on itself until the flamewar hits the "shrub event horizon" and dies for lack of oxygen. Linear conferencing retards flamewars. Users aren't offered a chance to respond to provocative material until after they've read the responses of other users who have, hopefully, already dealt with it.
In my experience, talking on a linear conferencing system is invariably a whole lot easier than talking on a threaded conferencing system. It's easier to navigate the system, it's easier to keep a mental model of the conversation, it's quicker -- less clicks are involved -- and, by golly, it's a lot easier to code.
BlogBlog hopes to combine WikiNature, BlogNature, and PicoNature.
(the syllable "Pico" here refers to PicoSpan, linear conferencing software written by Marcus Watts and put to its most influential use at the WELL, the WholeEarthLectronicLink. )
(You're absolutely right, but let's leave it in as an attributed comment. :))