Global Organization of the Lexicon

The lexicon consists of a set of word meanings and their semantic relationships. A systematic representation of the English lexicon based in psycholinguistic considerations has been put together in the database Wordnet in a long-term collaborative effort1. We present here a quantitative study of the graph structure of Wordnet in order to understand the global organization of the lexicon. We find that semantic links follow power-law, scale-invariant behaviors typical of self-organizing networks. Polysemy, the ambiguity of an individual word, can act as a link in the semantic network, relating the different meanings of a common word. Inclusion of polysemous links has a profound impact in the organization of the semantic graph, converting it into a small world, with clusters of high traffic (hubs) representing abstract concepts. Our results show that polysemy organizes the semantic graph in a compact and categorical representation, and thus may explain the ubiquity of polysemy across languages.