Recent research has been focused on how
to integrate domain ontology as background
knowledge to document clustering process
and shows that ontology can improve document
clustering performance with its concept
hierarchy knowledge (Hotho et. al., 2003; Jing
et. al., 2006; Yoo et. al., 2006). Hotho, Staab
and Stumme (2003) employed WordNet synsets
to augment document vector and achieves bet-