“…This theory is an extension of classical set theory for the study of systems characterized by insufficient and incomplete information, and has been demonstrated to be useful in fields such as pattern recognition, machine learning, and automated knowledge acquisition [14,27,[30][31][32]46,48]. Rough-set data analysis uses only internal knowledge, avoids external parameters, and does not rely on prior model assumptions such as probabilistic distribution in statistical methods, membership function in fuzzy sets theory, and basic probability assignment in Dempster-Shafer theory of evidence [7,33]. Its basic idea is to unravel an optimal set of decision rules from an information system (basically a feature-value table) via an objective knowledge induction process which determines the necessary and sufficient features constituting the rules for classification.…”