Granular Computing and Sequential Three-Way Decisions

Real-world decision making typically involves the three options of acceptance, rejection and non-commitment. Three-way decisions can be motivated, interpreted and implemented based on the notion of information granularity. With coarse-grained granules, it may only be possible to make a definite decision of acceptance or rejection for some objects. A lack of detailed information may make a definite decision impossible for some other objects, and hence the third non-commitment option is used. Objects with a non-commitment decision may be further investigated by using fine-grained granules. In this way, multiple levels of granularity lead naturally to sequential three-way decisions.