14. A non-transitory computer readable recording medium storing an ontology processing program which, when loaded into a memory and run by a computer, causes the computer to execute functions including: correcting a structure of ontology in a prescribed form created from a set of instance data containing a combination of a subject, a property, and an object expressed with a character string; judging whether each of the properties contained in the ontology is an essential property or an unessential property for a concept that is defined within the ontology and related to each of the properties according to statistical features of the objects contained in the set of instance data; correcting the structure of the ontology regarding the corresponding properties according to results of the judgments; and changing a property that is judged as unessential to a property having an inverted definition range and an inverted value range.
22. The non-transitory computer readable recording medium storing the ontology processing program as claimed in claim 14 , which enables the computer to execute a function of judging a dependent relationship between the properties and adding a hierarchical structure, or presenting a proposal of adding a hierarchical structure.