Clustering large files of documents using the single-link method

A method for clustering large files of documents using a clustering algorithm which takes O(n2) operations (single-link) is proposed. This method is tested on a file of 11,613 documents derived from an operational system. One property of the generated cluster hierarchy (hierarchy connection percentage) is examined and it indicates that the hierarchy is similar to those from other test collections. A comparison of clustering times with other methods showsthat large files can be clustered by single-link in a time at least comparable to various heuristic algorithms which theoretically require fewer operations.