On Tue, May 22, 2012 at 9:44 AM, Aaron Brown <abbr...@google.com> wrote:
> Ok. But I still don't see why this needs to be specified explicitly. > Otherwise, wouldn't it also be necessary to specify that a MedicalEntity is > disjoint from a Movie, a SocialEvent, a DryCleaningOrLaundry, etc? It seems > to get out of hand pretty quickly. For that matter, if someone wanted to > extend the proposed schema by defining a Physician type that inherits from > both Person and MedicalEntity, I think would be OK. > RDF and other semantic web standards allow for instances to have multiple unrelated types. This is part of the Open World Assumption, and is a good thing, since it allows us to discover classifications for things later on. In order to create the same sort of single inheritance that one sees in, for instance, Java, simply make each sibling under a given class disjoint with all its other siblings. I would be reluctant to do that blindly, though, as it can often result in modeling errors. For instance, Physicians are not the same thing as Patients, but a Patient can also be a Physician. Jim -- Jim McCusker Programmer Analyst Krauthammer Lab, Pathology Informatics Yale School of Medicine james.mccus...@yale.edu | (203) 785-6330 http://krauthammerlab.med.yale.edu PhD Student Tetherless World Constellation Rensselaer Polytechnic Institute mcc...@cs.rpi.edu http://tw.rpi.edu