17. A search system as claimed in claim 1 , wherein said weights are normalised, and said network is searched in response to a query by determining the inner product of said query vector and said weight vectors to locate nodes producing a high inner product.
17. A search system as claimed in claim 1 , wherein said weights are normalised, and said network is searched in response to a query by determining the inner product of said query vector and said weight vectors to locate nodes producing a high inner product. 18. A search system as claimed in claim 17 , including cluster means for processing indices output by said index means in response to said query, generating term frequency vectors for data indexed by said indices, comparing similarities between the indexed data on the basis of a distance between said frequency vectors and generating content based categories on the basis of said distances and placing the output indices into said categories for display.