A system for information clustering comprising a data accumulation part for accumulating documents in a document repository, the documents having loosely related attributes, and defining a cluster between the documents being time sliced so as to define chunks of the documents; a vector space generation part for generating document-keyword vectors, the document-keyword vectors consisting of sparse numeral values depending on presence of key words; a dimension reduction part for reducing dimensions of the keywords to create a dimension reduction matrix of the document-keyword matrix; a centroid vector determination part for generating a centroid vector of the cluster, the centroid vectors being defined from keywords and weight of documents within the cluster; and an item repository for storing the centroid vectors together with the keywords and the weights of the centroid vector.