This is an excerpt from a book that I found informative regarding the role of blog in online journalism practice:
1. commentary: opinion and analysis of news events or news coverage
2. filtering and editing: guiding and directing users to particular coverage or information
3. fact checking: challenging or verifying information previously written in the blog or in mainstream media content
4. grassroots reporting: providing eyewitness or firsthand accounts of news events
5. annotative reporting: supplementing a given story with additional source or background information
6. open-source reporting and peer review: submitting traditional reporting and information to review and revision by readers and other journalists.
