> For instance, Physicians are not the same thing as Patients, but a Patient > can also be a Physician. ....and a physician can be a patient, both of which are roles that entities can play. IMO, this illustrates the importance of defining roles and entities separately (rather than through inheritance from a common parent). Bob
________________________________ From: public-semweb-lifesci-requ...@listhub.w3.org on behalf of Jim McCusker Sent: Wed 5/23/2012 9:40 AM To: Aaron Brown Cc: Dan Brickley; Renato Iannella; Lin MD, Simon; Matthias Samwald; public-semweb-lifesci@w3.org Subject: Re: RDF Schema / LODD mapping -- Re: New proposal: health & medical extensions to schema.org 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 <http://krauthammerlab.med.yale.edu/> PhD Student Tetherless World Constellation Rensselaer Polytechnic Institute mcc...@cs.rpi.edu http://tw.rpi.edu <http://tw.rpi.edu/>