Affiliations: Department of Medical Informatics, Faculty of Medicine, Shimane University, 89-1 Enya-cho Izumo 693-8501 JAPAN. {tsumoto,hirano}@med.shimane-u.ac.jp
Note: [] Address for correspondence: Department of Medical Informatics, Faculty of Medicine, Shimane University. 89-1 Enya-cho Izumo 693-8501 Japan This research is supported by Grant-in-Aid for Scientific Research (B) 24300058 from Japan Society for the Promotion of Science(JSPS).
Abstract: This paper proposes a new framework for incremental rule induction of medical diagnostic rules based on incremental sampling scheme and rule layers. When an example is appended, four possibilities can be considered. Thus, updates of accuracy and coverage are classified into four cases, which give two important inequalities of accuracy and coverage for induction of probabilistic rules. By using these two inequalities, the proposed method classifies a set of formulae into four layers: the rule layer, subrule layer (in and out) and the non-rule layer. Then, the obtained rule and subrule layers play a central role in updating proabilistic rules. If a new example contributes to an increase in the accuracy and coverage of a formula in the subrule layer, the formula is moved into the rule layer. If this contributes to a decrease of a formula in the rule layer, the formula is moved into the subrule layer. The proposed method was evaluated on a dataset regarding headaches, whose results show that the proposed method outperforms the conventional methods.
