The Entity Describer (we call it "ED") helps people by making it easier for them to organize their Web-accessible bookmarks. It extends the traditional 'tagging' paradigm by allowing its users to use terms with unambiguous meaning in addition to personally created tags. For example, using ED, it is possible to tag this image of a mythical creature known as the 'hippocampus' with the special tag hippocampus and to tag this image of a part of a brain with the different special tag hippocampus.
By associating tags with URIs in computationally accessible knowledge representation/organization systems such as Freebase or the ontologies of the semantic web, ED allows people to very easily inform their computers what they are thinking when they add tags to resources on the Web. This, in turn, makes it possibe to create much richer interfaces for engaging with the collections produced through social tagging that take advantage of the additional structure built around the well-defined tags. Tag collections composed using ED can be browsed, searched, filtered etc. based on the kind of tag, for example, "show only 'medical' tags" or "show only 'anatomical' tags" or "show items tagged with both 'medical' and 'anatomical' tags".
In the present iteration, these semantically enhanced tags are drawn from Freebase topics. Freebase topics are much like Wikipedia articles, in fact many were originally based on automatically imported Wikipedia articles, but Freebase is not a wiki, it is a database. One particularly important and useful aspect of the topics in the Freebase database is that they can be associated with what are called 'Types'. For example, this hippocampus topic is of Type 'Mythological Figure' while this hippocampus topic is of Type 'Brain Structure' and Type 'Anatomical Structure'.
