Top-Level Ontologies

This section describes several approaches for upper, higher or top level ontologies. Interestingly enough, there is very few overlap between the different top level ontologies to date. So probably for a future widely acceptable top level ontology, one would probably have to choose the most accepted and practically usefull concepts from each of them.

• The 10 categories of Aristole still seem to be good candidates to be incorporated.
• The Basic Formal Ontology
• The General Formal Ontology
• The categories of the Sowa diamond have been much criticized for contradictions and incompleteness.
• The Cyc Ontology may be a little bit to technical and to much dedicated to the field of AI.
• One of the best candidates seems to be the Ontological Sextett ([ScSe2012], page 24) which has evolved from the classical ontological rectangle.Each of this top ontologies has been modelled in Ontology4 and is being represented as directed graphs in Ontology4 notation below.
• The Sumo ontology seems to be the most elaborated and practical upper ontology.
• Another important candidate for a upper level ontology certainly is the schema.org ontology. Its main purpose is to markup web pages with tags, which are recognized by the major search engines.
• UFO is another single coherent foundational ontology.

In the top-level ontologies, the foundational ontologies or formal ontologies are distinguished by the fact that they come with a formal axiom system. Among the formal ontologies we count BFO, DOLCE, GFO, O4Top and UFO.

"... one may doubt whether a final and uniquely determined top level ontology can be ever achieved" [HeHe2006a], page 1. We are pretty confident that with the O4Top ontology we propose, we have made a big step towards a general unifying top-level ontology..

Smith states in [Smit2005a], page 5: "In this connection it is worth bearing in mind that the term ‘formal ontology’ was originally coined by Husserl (1913/21) to signify that branch of philosophy which deals with the interconnections of things, with objects and properties, parts and wholes, relations and collectives – as contrasted with formal logic, which deals with the interconnections of truths, with consistency and validity, disjunction and entailment, ‘and’ and ‘not’."

We have made a comparison of the concepts used in the top-level and upper-level ontologies . It turned out that very few concepts are used in the same way. This makes it very difficult for ontology developers to choose one of these ontologies. Such a decision will be influenced to a large extent by how many of the top-level ontology concepts can be used in the development of one's ontology.

We also analyzed how many concepts, object properties and axioms are provided by the various top ontologies. Among them are by far the largest ontologies CYC and SUMO.

On page 2 of [HeHe2006a] we find: "Formal Ontologies combines the methods of mathematical logic with the analyses and princliples of philosophy. but also with the methods and princliples of other sciences, in particular artificial intelligence, cognitive psychology, and linguistics". At this point we would like to predict that future university education will have to be significantly intensified so that knowledge engineering is at least as important as education in the field of machine learning. However, the last discipline mentioned is currently also benefiting from an enormous hype, which has made the hibernation after the first wave of symbolic artificial intelligence forgotten.

Work on GFO startet in 1999 in the context of the GOL project (General Ontological Language). It was developed by Heinrich Herre and associates. GFO is now one component of a larger framework.

"The General Formal Ontology is a top-level ontology for conceptual modeling, which is being constantly further developed by Onto-Med".

• Latest intermediate revision: Version 1.0.1, Draft, 14.02.2007

Axiomatizations and Implementations

• The "native" formalization language for GFO is first-order logic (FOL). Partial axiomatizations of GFO in FOL exist in report working drafts, but are not yet available to the public.
• There is an OWL version of GFO, which currently comprises a stable core called gfo-basic.owl and a more extensive version called gfo.owl. The is a stable URL to the current releases of version 1.0, build 13, 07.10.2008 .

More detailed information on BFO is available on the ontobee.org website. BFO contains 35 classes, 22 annotation properties and about 78 object properties. It was developed by Barry Smith, Pierre Grenon and associates starting in 2002. About 300 ontology projects, mainly in the field of bio-medicine, use BFO as a foundational ontology,. Most recently, the BFO 2.0 OWL version was released.

"Descriptive Ontology for Linguistic and Cognitive Engineering (DOLCE) is a foundational ontology designed in 2002 in the context of the WonderWeb EU project, developed by Nicola Guarino and his associates at the Laboratory for Applied Ontology (LOA). As implied by its acronym, DOLCE is oriented toward capturing the ontological categories underlying natural language and human common sense. ",

"The Unified Foundational Ontology (UFO), developed by Giancarlo Guizzardi and associates, incorporating developments from GFO, DOLCE and the Ontology of Universals underlying OntoClean in a single coherent foundational ontology. The core categories of UFO (UFO-A) have been completely formally characterized in Giancarlo Guizzardi's Ph.D. thesis and further extended at the Ontology and Conceptual Modelling Research Group (NEMO) in Brazil with cooperators from Brandenburg University of Technology (Gerd Wagner) and Laboratory for Applied Ontology (LOA). UFO-A has been employed to analyze structural conceptual modeling constructs such as object types and taxonomic relations, associations and relations between associations, roles, properties, datatypes and weak entities, and parthood relations among objects. ... UFO is the foundational ontology for OntoUML, an ontology modeling language."

"OntoUML, is an ontologically well-founded language for Ontology-driven Conceptual Modeling. OntoUML is built as a UML extension based on the Unified Foundational Ontology (UFO). The foundations of UFO and OntoUML can be traced back to Giancarlo Guizzardi's Ph.D. thesis "Ontological foundations for structural conceptual models". In his work, he proposed a novel foundational ontology for conceptual modeling (UFO) and employed it to evaluate and re-design a fragment of the UML 2.0 metamodel for the purposes of conceptual modeling and domain ontology engineering."

"YAMATO is developed by Riichiro Mizoguchi, formerly at the Institute of Scientific and Industrial Research of the University of Osaka, and now at the Japan Advanced Institute of Science and Technology."