Lexical Chains
Lymba's lexical chain tool measures the semantic similarity between any two concepts or words. Lexical chains automatically builds paths between any two concepts defined in the eXtended WordNet Knowledge Base up to a reasonable distance. The meaning of these paths is that the concepts along the path are topically related, but not necessarily synonymous. An example of the output of the lexical chain tool for guitar and music might look like:
a guitar is a stringed instrument
a stringed instrument is a musical instrument
a musical instrument produces musical pieces
musical pieces are music
Therefore, guitar and music have a high semantic similarity.
For more details on lexical chains please refer to:Novischi, A.; Moldovan, D. "Question Answering with Lexical Chains Propagating Verb Arguments", Proceedings of ACL 2006, Sydney, Australia, 2006.