(α,β) reduction of decision table: A rough approach

Abstract

In this paper we generalise Pawlak’s rough approach for simplifying a decision table in an information system. We consider an information system where attribute values are not always quantitative,rather subjective having vague or imprecise meanings. Some objects may have attribute values which are almost identical i.e., they can’t be distinguishedclearly by the attributes. Considering this observation we present a generalised method for reduction of decision table for different choice values of α and β, α being for condition attributes and β for decision attributes where α, β ∈ [0, 1]. For α = 1 and β = 1, the method reduces to Pawlak’s method.