This is an updated version of the annotated bibliography at http://www.ontoclean.org. The goal of putting it on the wiki is that others who have written OntoClean-related papers can help maintain it. If you have written a paper that extends, analyzes, uses, etc., OntoClean, please feel free to add an entry here.

[edit] Core OntoClean Papers

• Guarino, Nicola and Chris Welty. 2004. An Overview of OntoClean. In Steffen Staab and Rudi Studer, eds., The Handbook on Ontologies. Pp. 151-172. Berlin:Springer-Verlag. Preprint: PDF.

  A very detailed exposition of how to use OntoClean, how to assign the metaproperties, and the results of OntoClean analysis, based on the ontology cleaning example that was presented in many OntoClean talks. The formalizations of the meta-properties are not presented. This is probably the last comprehensive paper on the core of OntoClean.

  • (Referred to as OntoCleanPaper in the definitions of metaproperties and modifiers.)
• Guarino, Nicola and Chris Welty. 2002. Identity and Subsumption. In Rebecca Green, Carol A. Bean, & Sung Hyon Myaeng (Eds.), The Semantics of Relationships: An Interdisciplinary Perspective. Pp. 111-125. Dordrecht: Kluwer. Preprint: PDF.

  A very detailed paper that includes numerous updates to the modal formalizations and cleans up some of the discussion of dependence. This is probably the last comprehensive paper on the axiomatizations of the core OntoClean meta-properties. The focus of this paper is a formal basis for correctly using the subsumption relationship. Interestingly, this paper began in 1999 as the first OntoClean paper, and the first three papers were essentially conference-sized slices of an earlier draft.

• Guarino, Nicola and Chris Welty. 2002. Evaluating Ontological Decisions with OntoClean. Communications of the ACM. 45(2):61-65. New York:ACM Press. Official Version: PDF, Preprint: PDF.

  A very high level view of OntoClean in CACM style. No formalizations are presented, mainly the intuitions of OntoClean and a concise discussion of the ontology modeling pitfalls that OntoClean analysis can expose, such as confusing constitution, part, instance, etc. with subclass. This is the most often cited OntoClean paper, the first to introduce the OntoClean name, and was ranked by Thompson-ISI as the most frequently cited paper in the emerging area of ontology design, as of June, 2004.

• Welty, Chris and Nicola Guarino. 2001. Support for Ontological Analysis of Taxonomic Relationships. J. Data and Knowledge Engineering. 39(1):51-74. October, 2001. Official Version: PDF, Preprint: PDF

  This was the journal-length version of the ER-2000 paper, that focuses more on the Q/A system, and a detailed run-through of the ontology cleaning example. Although longer than the conference papers, this is a good place to start because of the example focus. (Unfortunately, the list of questions referenced in the paper was lost when Chris moved from Vassar to IBM and simultaneously Nicola moved from Padova to Trento.)

[edit] Extensions to the OntoClean Core

• Welty, Chris and William Andersen. 2005. Towards OntoClean 2.0: a framework for rigidity. Journal of Applied Ontology 1(1):107-116. Amsterdam:IOS Press. Official version: PDF, Preprint: PDF.

  An exposition on rigidity surveying subsequent work on the notion and outlining different kinds, including temporal, alethic, etc. This paper was largely motivated by discussions at FOIS-04 during the presentation of [Andersen and Menzel, 2004], it occurred to us that there was nothing wrong with any of the rigidity axioms, just that there were different kinds. This work introduced two new metaproperties: permanence and actuality, and identified eleven different kinds of rigidity.

[edit] Uses of OntoClean

• Welty, Chris. 2006. OntOWLClean: Cleaning OWL Ontologies with OWL. In B. Bennet and C. Fellbaum, eds., Proceedings of FOIS-2006. IOS Press.

  This paper presents an OWL ontology of the original OntoClean metaproperties and a simple tool for generating views of OWL ontologies that allows the metaproperties to be assigned and the taxonomic constraints checked using an OWL-DL reasoner. The paper discusses the use of several semantic web tools (editors and reasoners) to do this task, and argues that something like this technique is required to provide a standard interchange for meta-property assignments.

• Oltramari, Alessandro, Aldo Gangemi, Nicola Guarino, and Claudi Masolo. 2002. Restructuring WordNet's Top-Level: The OntoClean approach. In K. Simov (ed.), Workshop Proceedings of OntoLex'2, Ontologies and Lexical Knowledge Bases (LREC2002). Las Palmas, Spain, May 27, 2002, pp. 17-26. Final Version: PDF.

  Presents an analysis and a rearrangement of WordNet's top-level taxonomy of nouns. A nice treatment of the limitations of WordNet as an ontology, especially in light of the OntoClean methodology. This is the first place that the origins of Dolce are presented as the "OntoClean top" (OCT), a set of top-level categories dictated by various meaningful combinations of the metaproperties. A “cleaned-up” WordNet results from this analysis, which is meant to be conceptually more rigorous, cognitively transparent, and efficiently exploitable in several applications.

• Völker, Johanna, Denny Vrandecic, and York Sure. 2005. Automatic Evaluation of Ontologies (AEON). In Y. Gil, E. Motta, V. R. Benjamins, M. A. Musen, eds. Proceedings of the 4th International Semantic Web Conference (ISWC2005), volume 3729 of LNCS, pp. 716-731. Springer Verlag:Berlin-Heidelberg, November 2005. Preprint: PDF.

  AEON is a tool which automatically tags concepts with appropriate OntoClean meta-properties based on linguistic patterns in web data. For example, one would expect the fragment, "... is no longer a student," to indicate that the class Student has changeable membership and thus is not rigid. While this is a clever and potentially very useful tool (given a sufficient set of patterns), one of the most interesting aspects of the paper is the section OntoClean in Practice, in which the authors discuss the experience of generating the so-called "ground truth" for the evaluation of the AEON technique. They found that for three human annotators, the agreement on metaproperty assignment was about 50% (dependence scored much lower).

[edit] Commentary, critiques and evaluations

• Andersen, William and Chris Menzel. 2004. Modal rigidity in the OntoClean methodology. In, Achille Varzi & Laure Vieu, eds., Formal Ontology in Information Systems: Proceedings of the Third International Conference. Amsterdam:IOS Press. Pp. 119-127. November, 2004.

  Proposed a new formalization of rigidity based on the relation between alethic modality and time. In [Welty & Andersen, 2005], this notion was incorporated into a more general framework as a kind of rigidity called temporally existential rigidity.

• Spolaore, Giuseppe, Pierdaniele Giaretta, Massimiliano Carrara, Marzia Soavi, and Vittorio Morato. 2004. Identity and Modality in OntoClean. In, Achille Varzi & Laure Vieu, eds., Formal Ontology in Information Systems: Proceedings of the Third International Conference. Amsterdam:IOS Press. Pp. 128-139. November, 2004.

• Welty, Chris, Ruchi Mahindru and Jennifer Chu-Carroll. 2004. Evaluating Ontology Cleaning. Proceedings of AAAI-2004. Pp. 311-314. San Jose:AAAI Press. July, 2004. Official version: PDF.

  When Mike Uschold first saw OntoClean he said, "Very interesting, but it seems like a lot of work. Is there any evidence that doing this work would pay off?" So we did this experiment with a search system that had a knowledge-based component. We cleaned up the KB using OntoClean and compared the precision and recall of the system with the clean KB and with the dirty KB. The cleaner KB did better.

• Kaplan, Aaron. 2001. Towards a consistent logical framework for ontological analysis. In, Barry Smith & Chris Welty, eds., Formal Ontology in Information Systems: Proceedings of the second international conference. New York:ACM. Pp. 244-255. October, 2001. Official version: PDF.

  Points out several errors in the original OntoClean formalization, mainly to do with inconsistent detail across the basic notions. Most of these errors were corrected in subsequent papers, the core papers in particular use Aaron's version of rigidity. In [Welty and Andersen, 2005], Aaron's version of the rigidity axioms were merged into a larger logical framework and called basic rigidity. The problem of triviality in identity criteria, pointed out here and elsewhere, is still open.

• Carrara, Massimiliano and Pierdaniele Giaretta. 2001. Identity Criteria and Sortal Concepts. In, Barry Smith & Chris Welty, eds., Formal Ontology in Information Systems: Proceedings of the second international conference. New York:ACM. Pp. 234-243. October, 2001. Official version: PDF.

  Some critiques of the formalizations including the triviality of identity criteria.

[edit] The three original OntoClean papers published in 2000

• Guarino, Nicola, and Chris Welty. 2000. Ontological Analysis of Taxonomic Relationships. In, Laender, A. and Storey, V., eds, Proceedings of ER-2000: The 19th International Conference on Conceptual Modeling. Berlin:Springer-Verlag LNCS Vol. 1920/2000. Pp. 210-224. October, 2000. Official version: PDF, Preprint: PDF.

  This paper covers mainly the constraints imposed by the meta-properties and the real value of the methodology for conceptual modeling, including the backbone taxonomy, and a simple Q/A system for guiding a conceptual modeler through the meta-property assignments. Finally, the taxonomy cleaning example is presented in medium depth, with some sample interactions with the Q/A system. A few errors in the published version are fixed in this on-line version. Interestingly, this paper was rejected from AAAI-2000 on the grounds that it ignored relevant work in the database community, but was nominated for best paper at ER-2000.

• Guarino, Nicola, and Chris Welty. 2000. A Formal Ontology of Properties. In, Dieng, R., and Corby, O., eds, Proceedings of EKAW-2000: The 12th International Conference on Knowledge Engineering and Knowledge Management. Berlin:Springer LNCS Vol. 1937/2000. Pp. 97-112. October, 2000. Official Version: PDF, Preprint: PDF.

  This paper describes mainly the ontology of property kinds. It is here that we first introduced the notion that often it is useful to know that a property carries a unity or especially an identity condition, even if the precise conditions can not be specified. We also first introduced here the importance of rigid properties in forming the backbone taxonomy of an ontology. Also here is an early version of the taxonomy cleaning example.

• Guarino, Nicola, and Chris Welty. 2000. Identity, Unity, and Individuation: Towards a Formal Toolkit for Ontological Analysis. In W. Horn, ed., Proceedings of ECAI-2000: The European Conference on Artificial Intelligence. Amsterdam:IOS Press. Pp. 219-223. August, 2000. Preprint: PDF.

  This paper provides very formal and rigorous definitions of identity and unity. The paper shows how we have adapted these notions from Philosophy in a way we believe makes them more applicable to conceptual modeling. We show how the standard interpretation of identity can be weakened to obtain a more practical notion of only-sufficient or only-necessary identity conditions. We show how the notion of Unity presented by Peter Simons can be adapted to establish when a class of entities are wholes. This paper also describes the notion of individual (something with unity and identity), and introduces an important meta-property for determining whether a class of entities carry unity and identity (though not how): countability. The paper then briefly discusses how these formal notions can be used to clarify taxonomic organization. This paper received a nomination for best paper.

[edit] Preliminary and Superseded papers

• Guarino, Nicola, and Chris Welty. 2000. A Formal Ontology of Properties (Preliminary Version). In Benjamins, R., Gomez-Perez, A., Guarino, N., and Uschold, M., eds, Proceedings of the ECAI-2000 Workshop on Applications of Ontologies and Problem-Solving Methods. August, 2000. Final Version: PDF.

  A preliminary version of the EKAW paper. Presents the same material, however the example has some problems as the analysis used is not completely described within the paper.

• Guarino, Nicola, and Chris Welty. 2000. Towards a methodology for ontology-based model engineering. In, Bezivin, J. and Ernst, J., eds, Proceedings of the ECOOP-2000 Workshop on Model Engineering. June, 2000. Final version: PDF.

  This was the earliest published version of the notions underlying our methdology, but was superceded by the final version of the more comprehensive ER-2000 paper above. This paper covers our meta-properties for property analysis at a medium level of rigor, with intuitive descriptions of all the meta-properties, and formalizations of the meta-properties for carrying identity and unity conditions. The additional assumptions we make and the constraints that follow from our defintions are discussed with examples, unlike the draft ER paper. The backbone taxonomy is introduced, and the taxonomy cleaning example is presented in greater detail than the ER paper, as well as being consistent to the notions within the paper, unlike the preliminary Formal Ontology of Properties paper.

[edit] Precursors to OntoClean

• Guarino, Nicola. 1999. The role of Identity Conditions in Ontology Design. Proceedings of the IJCAI-99 Workshop on Ontology and Problem Solving Methods (KRRS), Stockholm, Sweden, August 2, 1999. Republished in C. Freksa and D. M. Frank (eds.), Spatial Information Theory: Cognitive and Computational Foundations of Geographic Information Science, Springer Verlag 1999. Amended version: PDF.

  This paper presents the early notions of how identity conditions can be used to make ontologies, and especially taxonomies, more clear. It mainly revises the Ontological Principles for Designing Upper Level Lexical Resources paper below. This paper covers a minimal ontology of particulars, including levels of ontological stratification based on common types of identity conditions, a slightly updated version of the list of problems with existing ontologies such as CYC, Mikrokosmos, Pangloss, WordNet, and Penman, as well as notions that have been superceded by the more recent papers, including the meta-properties for identity, rigidity, and dependence, and a minimal ontology of universals.

• Guarino, Nicola. 1998. Some Ontological Principles for Designing Upper Level Lexical Resources. Proc. of the First International Conference on Lexical Resources and Evaluation, Granada, Spain, 28-30 May 1998. Final version: PDF.

  This paper is mainly superceded by the above Role of Identity Conditions in Ontology Design. It was the first paper that introduced the list of problems with existing ontologies such as CYC, Mikrokosmos, Pangloss, WordNet, and Penman. The description of the levels of ontological stratification are more detailed than the subsequent paper.

OntoClean