Ross Mayfield draws a useful distinction, responding to Fredrik Wack’s taxonomy of enterprise weblogs
Instead of the next six types Fredrik offers, I’d suggest the simple categorization of if the blog has a single or multiple authors. Inside the enterprise group blogs are more common and oriented towards collaboration. The topic or objective of a blog can change over time, as most things do, and most individual blogs defy categorization.
Building on these points: knowledge and collaboration aren’t different kinds of blogs — they are different stages in the lifecycle of the same post.
For example, at Socialtext, we use a team weblog to collaborate on the release process, logging process steps, and keeping the team up to date. Once the release is done, the posts serve as an archive. Because Socialtext uses a wiki repository, blog posts can be linked to by name, and updated later.
A post starts as live collaboration, and turns into a knowledge base over time.
Also, today’s technology is blurring the distinction between individual and group blogs in a corporate and community settings. Aggregators, portals, and metablogs pull together individual blogs into combined views of the conversation in the community.