Inference in hybrid KBS with interval-valued confidence

This article discusses confidence handling for inference in hybrid knowledge-based system (KBS) with hierarchical knowledge representation. The knowledge content (precise or imprecise) represented in multiple units of knowledge hierarchy and the confidence obtained during inference process are treated as two levels separately but simultaneously based on the concept of truth value flow inference. Three-parametric triangular truth values as special subsets defined on the interval [0,1] are adopted to describe the confidence of inference, and operations on such interval-valued confidence are defined to meet commonsense interpretation of decision making.