The paper by Yiyu Yao explores the concept of three-way decisions in the context of rough set theory, which approximates a concept using three regions: positive, boundary, and negative. These regions correspond to decisions of acceptance, abstention, and rejection, respectively. The analysis is conducted in both the classical rough set model and the decision-theoretic rough set model, enriching the theory with ideas from Bayesian decision theory and hypothesis testing in statistics. The paper highlights the practical applications of three-way decisions, particularly in scenarios where errors and costs are significant. It also discusses the limitations of the classical model and proposes a decision-theoretic approach that incorporates probabilistic measures and cost-based analysis. The paper further examines the application of these concepts in two-category classification problems, providing detailed formulations and interpretations of the rules.The paper by Yiyu Yao explores the concept of three-way decisions in the context of rough set theory, which approximates a concept using three regions: positive, boundary, and negative. These regions correspond to decisions of acceptance, abstention, and rejection, respectively. The analysis is conducted in both the classical rough set model and the decision-theoretic rough set model, enriching the theory with ideas from Bayesian decision theory and hypothesis testing in statistics. The paper highlights the practical applications of three-way decisions, particularly in scenarios where errors and costs are significant. It also discusses the limitations of the classical model and proposes a decision-theoretic approach that incorporates probabilistic measures and cost-based analysis. The paper further examines the application of these concepts in two-category classification problems, providing detailed formulations and interpretations of the rules.