Everyone nowadays repeat the same mantra of web 2.0, but somehow this project managed to say things sets it apart:
..users are no longer limited to consuming or creating online content, they also provide the semantic scaffolding holding together such content, thus taking on an active role in shaping the architecture of online information. The collaborative character underlying many Web 2.0 applications puts them in the spotlight of complex systems science,.."Semantic scaffolding holding together .. content", that's a pretty awesome way to put it!
The paper "Vocabulary growth in collaborative tagging systems" investigates the temporal evolution of a tagging vocabulary size (of delicious) both on a
- global level (the number of distinct tags in the entire system) and
- local level (the growth of the number of distinct tags used in the context of a given resource or user).
The paper finds out that the growth behaviours are remarkably regular throughout the entire history of the system with power-law behaviours with exponent smaller than one (non of that "fat head and long thing tail"!) and across very different resources being bookmarked.
Moreover, they find that there are some intrinsic characteristics of the system which do not depend strongly on the size of the dataset, like that the average number of tags is about 3.4 (local level). If I get it all right, they conclude on this that on the local scale (resource or user) "all curves tend to lie along a "universal" growth curve with an exponent close to 2/3".
The authors of this paper also highlight that the tools and concepts from complex system science may prove valuable for understanding the structure and dynamics of folksonomies.
Some interesting papers towards this direction: http://www.furl.net/members/vuorikari/semiotic_dynamics