
146 Introduction to Soft Computing
in the areas of machine learning, knowledge acquisition, decision analysis, knowledge discovery from
databases, expert systems, inductive reasoning and pattern recognition. Rest of this chapter provides an
introductory discussion on the fundamentals of the Rough set theory.
5.1 INFORMATION SYSTEMS AND DECISION SYSTEMS
A datum (singular form of the word ‘data’) is usually presented either as a number, or a name. ‘Infor-
mation’ is processed or structured data that may convey some meaning. Data in itself do not carry
any meaning, and therefore useless for practical purposes. However, when interpreted in a particular ...