| 摘要 |
PROBLEM TO BE SOLVED: To generate a class which is free from redundancy and has generality by determining respective classes while making them correspond to respective nodes which do not always have the same layer depth suitable for classing as to thesaurus information wherein words are classified hierarchically in tree structure. SOLUTION: As an initial state, respective words are classified into classes which are in the shallowest layer, i.e., have the highest degree of abstraction (1, 2). At this time, the number of the classes is the least. Then one class is selected out of those classes (3), the layer of the thesaurus is made one layer deeper to increase the number of classes, and entropy is calculated (4). The selected class is put back and similar trial is carried out for all the classes (6); and the class where the entropy decreases most through fractionation is determined and the fractionation is carried out. The respective classes which are thus determined correspond to nodes in layers of different depth of the thesaurus information generally by the classes. |
