Multiplicity. How many people add to a kind of collective intelligence. A prominent example in my mind is Wikipedia, where users can add and alter the info pages regarding various subjects.

The advantage of this system is freedom of use and knowledge that is up to the minute and constantly evolving, unlike a printed encyclopedia whose information can become dated within a space of years.

This disadvantage is that in reality about ‘50% of the edits are done by 7% of the users’ as per the link below

http://www.aaronsw.com/weblog/whowriteswikipedia

So we may not nessecarily be getting information made up of a wide and varied contribution - rather a limited one of a few key contributors. The information may be biased and unbalanced as a result.