Using word clusters to detect similar web documents

It is relatively easy to detect exact matches in Web documents; however, detecting similar content in distinct Web documents with different words and sentence structures is a much more difficult task. A reliable tool for determining the degree of similarity between any two Web documents could help filter or retain Web documents with similar content. Most methods for detecting similarity between documents rely on some kind of textual fingerprinting or a process of looking for exactly matched substrings. This may not be sufficient as changing the sentence structure or replacing words with synonyms can cause sentences with similar/same content to be treated as different. In this paper, we develop a sentence-based Fuzzy Set Information Retrieval (IR) approach, using word clusters that capture the similarity between different words for discovering similar documents. Our approach has the advantages of detecting documents with similar, but not necessarily the same, sentences based on fuzzy-word sets. The three different fuzzy-word clustering techniques that we have considered include the correlation cluster, the association cluster, and the metric cluster, which generate the word-to-word correlation values. Experimental results show that by adopting the metric cluster, our similarity detection approach has high accurate rate in detecting similar documents and improves previous Fuzzy Set IR approaches based solely on the correlation cluster.