At the Indiana Philosophy Ontology (InPhO) Project, we are working to create a dynamic formal ontology for the discipline of philosophy. This knowledge representation is currently being developed primarily to serve the metadata needs of the Stanford Encyclopedia of Philosophy (SEP), although it may have a wide array of other uses.
The SEP is a peer-managed, open-access, dynamic reference work, with new entries constantly being published and old entries asynchronously edited. This creates a serious challenge: how can the SEP's metadata (cross-references, tables of contents, search keywords) be efficiently updated to reflect the changing content? Our approach to the problem is to combine statistical co-occurrence methods with expert feedback to create a dynamic semantic representation of the items described in the SEP's articles.
The InPhO contains categories for persons, documents, organizations, and, most importantly, philosophical ideas. The "person" ontology currently contains a great deal of biographical information about philosophers, and we are working on populating our "document" ontology with a full array of citation information. However, our taxonomy of philosophical ideas is the most useful area of the ontology for addressing the SEP's metadata needs. This taxonomy is generated by first using co-occurrence statistics to produce ranked candidate lists of hypernym and hyponym candidates for each idea term, which are then passed to SEP authors for evaluation. With the authors' feedback in hand--which gives us expert judgments of the relative similarity and generality of terms in the SEP--we can use answer set programming techniques to construct an taxonomy classifying these ideas according to their location in the "intellectual space" of the discipline. (To view a browsable representation of the current draft of the idea ontology, click on the "taxonomy" link to the right.)
