The person and organization ontology (also called the identity ontology) is a general ontology that is being used by several applications and that is not tied to a specific domain. We are considering two existing alternatives that could be used as such. Using an existing general purpose ontology instead of creating our own identity ontology for the KP-Lab system is a good choice because of the general nature of the domain being modelled and because of the benefits of familiarity and interoperability that the use of a standard ontology brings. We will now present the two existing ontologies that are under consideration: vCard and FOAF .
The vCard standard is an electronic business card profile defined by RFC 2426. In this document, we are interested in the RDF vCard specification which provides the functionality of vCard in RDF. The majority of the vCard property types have strings as their values and are simply represented by their property type name and value as specified in the vCard specification. These include: FN, NICKNAME, BDAY, MAILER, GEO, TITLE, ROLE, CATEGORIES, NAME and SOURCE. The properties just listed are self-explanatory except for the property SOURCE which maps to the RDF "about" URI and should be used to indicate the unique identifier for the person object. Another property that deserves an explanation is NAME. It is a human-displayable text about the vCard record itself and not the person. Several vCard properties have type parameters that may be used to describe it in more detail. For example, the address may be a work address or a home address. In some cases the type parameter may take a value specified outside the vCard specification. The properties where this is the case are: UID, LOGO, PHOTO and SOUND. For example, one could use as the UID the Finnish social security number.
The FOAF specification describes a language that consists of classes and properties. FOAF was originally developed to describe people, but it is a constantly evolving vocabulary. Unlike vCard, FOAF was originally written using RDF/OWL.The vCard standard is more concise than FOAF and it is a closed standard, meaning that once an organization has settled on using a certain version of it, it cannot be extended. On the other hand, the FOAF vocabulary may be freely extended with new terms. In fact, it is not developed in the same way as industry standards, but rather in the same way as free open source software.
The current requirements for storing information about the users of the KP-Lab System do not present a need for a very expressive identity ontology concerning persons. The properties required so far include: email, isMemberOfGroup, portrait, familyName and givenName. However, there is a need for being able to model information concerning also groups and organizations and this is why the simple vCard standard is not expressive enough for our purposes. An example of a the usage of FOAF in the Person and Organization ontology is presented in the following files: in RDFM 24 Person And Organization Ontology/personOrganization.rdf-xml.owl and as a Protege project M 24 Person And Organization Ontology/personOrganization.pprj.
Examples of classes used:
The person and organization ontology is linked to the security ontology through the application specific ontologies because the roles of persons, groups and organizations are application specific. The information about personal user preferences and configurations are also modelled in the application specific ontologies.
The class Agent is also an object of activity. Thus, it inherits all properties of the class tlo:ObjectOfActivity.