Diverse Data on an Epic Scale
In Web 2.0, data is often as important as function. Take
del.icio.us as an example: its functionality is voluntarily lim-ited to the basic function of bookmarking with tags, how-ever, the value of del.icio.us emerges from the massive amount
of annotated resources. Thus Web 2.0 services employ dif-ferent measures for increasing user contributions and partic-ipations, for instance by building trust (e. g., oering users
to leave with an export of their data), by explicit licenses
(often open licenses such as Creative Commons), and para-doxically, by making content accessible through RSS syn-dication and APIs. Behind the user-provided data of Web
2.0 lies the Semantic Web [10] with its vision to make the
data currently hidden in databases available for usage by
machines.
As a result, Web 2.0 enables access to data at an unprece-dented scale, such as pictures (e. g., Flickr)
4
), bookmarks,
mapping data (e. g., Google Maps), but also indexed data,