This article comments on data mining and rough
set theory, regarding the article "Myths About Rough Set Theory,"
published in the November 1998 issue of the journal "Communications of the
ACM." The authors of this article raise some important issues and express
some legitimate concerns. The authors express that rough data set theory is not
the only discipline in which discretization is necessary or deals with complex
data, cited as two problems. The third problem raised by the authors is
associated with the difference between objective and subjective approaches to
uncertainty. The article explains each problem with examples of grading student
work, a table of 10 attributes with 20 values each to illustrate complexities
involved in data analysis. As per the article, discretization is a technique
used in many areas, including machine learning and learning in networks, and is
definitely not restricted. Finally, regarding the authors' comments about
objectivity of rough set theory, the author related Dempster-Shafer theory and
the rough set theory, citing the definition of probability, as an example. The
author concluded that input data must be given to initiate rough set theory
procedures, and when rough set theory comes into the picture, its methods are
objective with respect to given data.