5.8 Chapter BiBliography 221
rough approximation was described by [Slowinski 2000]. [Cattaneo 1997]
introduced generalized rough sets. The extension of rough sets for data
mining is described by [Lingras 1998]. Rough sets used for feature selec-
tion and classification was reported by [Bao 2001], [Deogun 1998], [Lin-
gras 2001], and [Zhong 2001].
Information retrieval is another area where rough-set theory was applied
for data mining. [Miyamoto 1998], [Ramanna 2002], and [Possas 2002] pro-
posed various methods for information retrieval based on rough sets. [Hirano
2001] introduced a knowledge-oriented clustering technique based on rough
sets, whereas [Ruhe 1994] showed how data analysis based on rough sets
could be perfor ...