Difference Between Frames and Description Logic

This post has the goal to discuss in few lines the differences between Frames Technology and Description Logic Based Languages. For the ones that don’t know these terms, OO languanges are Frame based, and OWL is a Description Logic Language. The differences between this two worlds are important because when we are working with ontologies it is a common practice model in a O.O. modeling language (UML) and later translate it to a Description Logic Language (OWL-lite or OWL-DL). If we aren’t aware of the differences between the two worlds we can have some problems when doing the mapping between the model and its implementation.

A DL terminology includes a set of primitive concepts and roles(properties) as well as definitions of complex concepts and roles. The definitions of complex concepts and roles are given via descriptions that are built using a set of constructors, which vary from one DL to another. The strength of DLs is that they are associated with algorithms for subsumption checking, automatic classification and instance recognition.[1]

Frame logic (FL) accounts in a clean, declarative fashion for most of the structural aspects of object-oriented and frame based languages[3]. F-logic stands in the same relationship to the object oriented paradigm as classical predicate calculus stands to relational programming. Although the Frames Technology most well known example is the OO programming languages, there are some ontology languages based on Frames, one example is F-Logic, and the Protégé itself one of the most known ontology editors is based on frames. There is also a reasoner to F-Logic called Florida[2].

• DLs rely on the ontological distinction between concepts and elements. FL blows away this distinction.
• FL: closed-world and domain-closure assumptions. DL: open-world and open-domain assumptions.
• FL: class definition necessary and sufficient.
• DL don’t uses the unique name assumptions[4] whereas FL includes term equality.
• DL don’t provides control knowledge. The user it is only able to provide declarative knowledge.

I need to do some research yet to understand how protégé works since it is a frame based editor, but OWL more used is the OWL-DL.

[1] D. Fensel, M.-C. Rousset and S. Decker – Workshop on Comparing Description and Frame Logics

[2] http://en.wikipedia.org/wiki/F-logic

[3] Logical Foundations of Object Oriented and Frame Based Languages – Michael Kifer, Georg Lausen and James Wu

[4] http://en.wikipedia.org/wiki/Description_logic