I want to add to Brandon Davis-Shannon post about Distributed Conversations
I am afraid that by using blog posts and comments as a web forum we are returning back to the ugly type of threaded web forums used in the ’90s, I prefer the linear (flat) discussions.
You can read more about the differences between blogs and web forum discussions:
Weblogs or blogs are being heralded as the “next big thing” in education. In this article we examine the advantages and disadvantages of this form of Internet-based interaction using the Community of Inquiry model with its focus on social, cognitive and teaching presences. We conclude that blogging has distinct advantages over more common threaded discussion in its support of style, ownership and identity, and its public nature may enhance resolution phases of cognitive presence. However, its lack of safety and the current inefficiencies of linking and threading messages present greater challenges than the more familiar threaded discussion or email list. Perhaps the blog’s greatest relative advantage is for non formal and open education that takes learning beyond the traditional course.
Source: International Journal of Instructional Technology and Distance Learning
Weblogs and Message Boards both allow for responses from the community- new topics can be responded-to by others. Weblog topics have comments and message board topics have replies. This subtle difference in syntax reveals a difference in the roles. The word comment for weblogs implies that the author does not need further participation to reach a goal- comment if you want. Reply, on the other hand, implies that participation is explicitly requested by the poster. A discussion is not a discussion without a reply.
Source: Common Craft
To a large extent, blogging and forum use correlated with specific individual learning styles and media affordances: the use of blogs was associated with the ability to create personal space for personal learning, quiet reflection and developing personal relationships with bloggers and others. The use of forums was associated with fast paced challenging interaction, relationships based on sharing of ideas, more open discussion and more links to the discussed themes and bigger picture.
Source: Networked Learning Conference 2010
Online Sapiens 
Just to clarify and build (because I think we agree): I don’t think we should equate forums and blogs or try and replace forums with blogs (I like that Common Craft link above, very enlightened). When I talk about my preference for blogs, I am talking about a certain pedagogical stance that favors individual student exploration and the active creation of connections between students. I think that forums tend more towards focused discussion on assigned topics and having built in connections between students through the form of the forum. Of course, neither blogs nor forums rule out other kinds of interactions (however, a single centralized blog for discussion is, in my opinion, a poor man’s forum–it’s a shame, then, I used one as a forum replacement this past summer!), but they do tend towards certain kinds of interactions.
By: Brandon Davis-Shannon on September 12, 2011
at 1:40 pm
I’m not as certain about this as I used to be. I am a BIG fan of Moodle forums for studying academic subjects, where you need to stay focused. I think blogging and commenting may be more appropriate for the self-referential stuff (i.e. web learning about the web) because it more approximates broader web-based communications. I noted on Brandon’s blog my latest post on this as regards this SMOOC (http://lisahistory.net/wordpress/2011/09/a-funny-thing-happened-on-the-way-to-the/) but as always feel free to disagree! I am by no means certain of my view.
By: Lisa M Lane on September 13, 2011
at 3:30 am