Property re-use - Rules for identifying properties with identical semantics

[jechterhoff]

Description

In UML an attribute belongs to the class that defines it. Likewise, an association role is a property that also belongs to a specific class. See the following figure (ignore the arrows for now).

In RDF, a property can be described in terms of the classes (of resource(s)) to which it applies but it can also be described independently of any class.

Apparently there is a mismatch between UML and RDF: in UML a property belongs to its class while in RDF a property can be used by / in the domain of multiple classes. In the figure, the properties highlighted with arrows would be candidates for global definition within an RDF schema, to be reused by multiple classes.

When transforming INSPIRE data models to RDF vocabularies, we need to have clear guidance on how to transform class properties.

A straightforward solution would be to transform each property to its own RDF property definition, through augmentation with the class name that the property belongs to in UML. However, if multiple properties with the same name and the same semantics exist in a schema this would lead to repetition that would clearly be undesired and not in the spirit of RDF. In this case, there should be a way to identify which properties can be reused, i.e. mapped to a common property definition. Reuse can happen within a vocabulary and between multiple vocabularies. Reuse of property definitions from external vocabularies may also be an option.

Discussion Item

Which rules exist for identifying properties with identical semantics?

Aspects to consider for these rules:

• If they cover all model situations
• If conflicting situations can arise, and how can they be handled
• Which of these rules can be automated

[jechterhoff]

Also see section Domain - local vs. global of the guidelines.