The fundamental problem that semantic web needs to solve is explaining the meaning of things to computers.There are several approaches to this, all of which in principle can work.
There are companies and technologies that are doing it bottom up - by embedding semantical annotations (meta-data) right into the data. The opposite camp is exploring the top-down approach, which relies on analyzing existing information.
The ultimate top-down solution would be a fully blown natural language processor, which is able to understand text like people do.
Download ebooks on http://www.frenchtheory.com/
See that post with different algorithms in metabole
See the journal French Metablog with today different posts
