Abstract: The application which deals with the uncertain or vague information, the rough set theory is a useful and major method in the decision making. Rough set theory provides a feasible approach for decision rule extraction. This paper discusses the basic concepts of rough set theory as data representation, lower approximation, and upper approximation, attribute selection and rule formation. We have also discussed some application areas of rough set theory in the field of data mining and sensor networks.

Keywords: rough set theory, lower approximation, upper approximation, data mining, rule extraction.