ABSTRACT
Great progress has been made in the £elds of Web technology development and applications, and it has speeded up integration of the Web with personal and societal uses. Especially, Web 2.0 technology leads to the formation of Web ecology, in which humans, digital environments, and digital resources coexist and will evolve for a long time. Just like in the realworld ecology, human factors play an important role in the Web ecology. People are active in all kinds of activities, such as creating new types of digital contents, interacting with each other, pushing the formation of opinion, etc. By analyzing and modeling user activity for the Web, the how and why of complex phenomena in Web ecology are expected to be revealed gradually.
