OWL terminology: why individuals have ObjectProperties (instead of IndividualProperties)

Question

In the W3 OWL specification, the properties of individuals are divided into two groups: data type properties and object properties. The properties of the object are defined (as one article, I found it):

"The properties of an object (owl: ObjectProperty) bind individuals (instances) of two OWL classes.

Thus, in essence, the properties of an object can also be called "individual properties", since they do not simply indicate universal objects of any type, they indicate specifically individuals.

Now, if it were some random specification, I would suggest that the authors simply chose their names incorrectly, but this is the W3 specification and one specifically for storing knowledge is no less; I must assume that people thought about the names of things!

Therefore, I hope that someone here can explain this seemingly strange choice of naming. After all, you can call damn almost anything in any spec "ObjectFoo" because Object is a super-generic term, but usually people use the maximum possible term, not least when they name things.

Maybe, in another case, when ObjectProperty can refer to something other than an individual person, or to something else that I am missing, what can explain this?

Answer 1

The term "ObjectProperty" was (most likely) coined to distinguish it from "DatatypeProperty", in the sense that the latter can only have (datatyped) literal values, not complete objects. And yes, these are not just people who can be ObjectProperty values, classes can also be their values ​​- although if you do, your ontology is no longer valid OWL DL and instead becomes OWL Full. But this is true in terms of modeling.

Answer 2

My answer is also a comment on Gene. OWL DL and OWL Full are two different languages ​​with a different (even disjoint) abstract syntax. The OWL DL syntax is defined in terms of a structural specification . The full OWL syntax is RDF. The OWL structural specification does not even contain an RDF triple.

Now, in OWL DL, it is incorrect to bind two classes to an object property. Object properties can only apply to owl:Thing instances. They cannot bind literals, properties, ontologies, or data types. If you invoke the IndividualProperty concept, you create name mismatches because DatatypeProperty does not mean a property that binds data types. This is the property that binds literals. Therefore, the best name would be ClassProperty . Or you will have to change both DatatypeProperty and ObjectProperty to LiteralProperty and IndividualProperty .

In general, there are various ways to deal with this, the working group chose the one that collected more votes. That's all that he always works in a standardization group.

Answer 3

The name comes from the Predicate Object object. These are properties that bind an object to an object, opposite the Datatype properties, which are just attributes.