How do people co-create information environments?

PeterMe's post about emergent IA--go read it, then come back--reminded me of some work I did back in March.

While putting together my IA Summit panel I did an internal presentation on social information architecture where I talked at the different ways users can add structural value to websites. (In the IA world we're mainly concerned with structure that helps people find, use and interact with information.)

In the talk I was explicitly trying to put tags in the context of all the things people could do that could potentially add that structural value. Here's the diagram I created:

The size of the bubbles is supposed to indicate, roughly, how valuable each "action" is. I didn't think to include wiki-related actions but (obviously) they would be in the upper-right quadrant.

One thing jumps out at me after reading Peter's post: another way of looking at the x-axis is by the degree to which algorithms are required to create structure. For something like page views, it's nearly 100% (you still need people to click on links). As Peter notes, in the case of the wiki it's nearly 0%--once the basic wiki software is in place, people create everything.

I think the kinds of actions a site allows--and where they fall on the implicit-explicit continuum--also affects the amount of user-contributed structure you can expect. I made this scale diagram for my internal presentation to show the range of possibilities:

(In hindsight, I'm not really sure that mashups belong on the far right.)

I ended up tweaking this for my IA Summit panel intro to show how much structure users contribute to Ebay, Amazon, Del.icio.us and Wikipedia:

Unfortunately this disguises the fact that the most pressing problem most of us have is getting enough participation to make user-contributed structure viable in the first place.

Anyway, almost of all of this will resurface in a couple of weeks at my Webvisions talk.