Ontology Matching Task
An Ontology Matching Task is a knowledge base record matching task for the ontology records of two or more ontologies.
- AKA: Ontology Mapping/Alignment.
- Context:
- Input: two or more Ontologies.
- output: a Ontology Matching Structure (between ontology concepts).
- It can be solved by an Ontology Mapping System (that applies an ontology matching algorithm).
- It can range from being a Heuristic Ontology Matching Task to being a Data-Driven Ontology Matching Task (such as supervised ontology matching).
- It can range from being a Lexicalized Ontology Matching Task (such as multi-lingual ontology matching) to being a Formal Ontology Matching Task.
- It can range from being a Lightweight Ontology Matching Task to being a Heavyweight Ontology Matching Task.
- It can support an Ontology Merging Task.
- …
- Counter-Example(s):
- See: Ontology Alignment Evaluation Initiative (OAEI), Ontology Visualization, Data Integration, Semantic Heterogeneity.
References
2016a
- (Wikipedia, 2016) ⇒ http://wikipedia.org/wiki/Ontology_alignment#Computer_Science Retrieved:2016-3-4.
- For computer scientists, concepts are expressed as labels for data. Historically, the need for ontology alignment arose out of the need to integrate heterogeneous databases, ones developed independently and thus each having their own data vocabulary. In the Semantic Web context involving many actors providing their own ontologies, ontology matching has taken a critical place for helping heterogeneous resources to interoperate. Ontology alignment tools find classes of data that are “semantically equivalent," for example, "Truck" and "Lorry." The classes are not necessarily logically identical. According to Euzenat and Shvaiko (2007),[1] there are three major dimensions for similarity: syntactic, external, and semantic. Coincidentally, they roughly correspond to the dimensions identified by Cognitive Scientists below. A number of tools and frameworks have been developed for aligning ontologies, some with inspiration from Cognitive Science and some independently.
Ontology alignment tools have generally been developed to operate on database schemas, [2] XML schemas,[3] taxonomies, [4] formal languages, entity-relationship models, [5] dictionaries, and other label frameworks. They are usually converted to a graph representation before being matched. Since the emergence of the Semantic Web, such graphs can be represented in the Resource Description Framework line of languages by triples of the form <subject, predicate, object>, as illustrated in the Notation 3 syntax. In this context, aligning ontologies is sometimes referred to as "ontology matching". The problem of Ontology Alignment has been tackled recently by trying to compute matching first and mapping (based on the matching) in an automatic fashion. Systems like DSSim, X-SOM or COMA++ obtained at the moment very high precision and recall. The Ontology Alignment Evaluation Initiative aims to evaluate, compare and improve the different approaches.
More recently, a technique useful to minimize the effort in mapping validation and visualization has been presented which is based on Minimal Mappings. Minimal mappings are high quality mappings such that i) all the other mappings can be computed from them in time linear in the size of the input graphs, and ii) none of them can be dropped without losing property i).
- For computer scientists, concepts are expressed as labels for data. Historically, the need for ontology alignment arose out of the need to integrate heterogeneous databases, ones developed independently and thus each having their own data vocabulary. In the Semantic Web context involving many actors providing their own ontologies, ontology matching has taken a critical place for helping heterogeneous resources to interoperate. Ontology alignment tools find classes of data that are “semantically equivalent," for example, "Truck" and "Lorry." The classes are not necessarily logically identical. According to Euzenat and Shvaiko (2007),[1] there are three major dimensions for similarity: syntactic, external, and semantic. Coincidentally, they roughly correspond to the dimensions identified by Cognitive Scientists below. A number of tools and frameworks have been developed for aligning ontologies, some with inspiration from Cognitive Science and some independently.
- ↑ Jérôme Euzenat and Pavel Shvaiko. 2007. Ontology matching, Springer-Verlag, 978-3-540-49611-3.
- ↑ J. Berlin and A. Motro. 2002. Database Schema Matching Using Machine Learning with Feature Selection. Proc. of the 14th International Conference on Advanced Information Systems Engineering, pp. 452-466
- ↑ D. Aumueller, H. Do, S. Massmann, E. Rahm. 2005. Schema and ontology matching with COMA++. Proc. of the 2005 International Conference on Management of Data, pp. 906-908
- ↑ S. Ponzetto, R. Navigli. 2009. "Large-Scale Taxonomy Mapping for Restructuring and Integrating Wikipedia". Proc. of the 21st International Joint Conference on Artificial Intelligence (IJCAI 2009), Pasadena, California, pp. 2083-2088.
- ↑ A. H. Doan, A. Y. Halevy. Semantic integration research in the database community: A brief survey. AI magazine, 26(1), 2005
2016b
- (Wikipedia, 2016) ⇒ http://wikipedia.org/wiki/Ontology_alignment#Formal_Definition Retrieved:2016-3-4.
- Given two ontologies [math]\displaystyle{ i=\langle C_{i}, R_{i}, I_{i}, A_{i}\rangle }[/math] and [math]\displaystyle{ j=\langle C_{j}, R_{j}, I_{j}, A_{j}\rangle }[/math] we can define different type of (inter-ontology) relationships among their terms.
Such relationships will be called, all together, alignments and can be categorized among different dimensions:
- similarity vs logic: this is the difference between matchings (predicating about the similarity of ontology terms), and mappings (logical axioms, typically expressing logical equivalence or inclusion among ontology terms)
- atomic vs complex: whether the alignments we considered are one-to-one, or can involve more terms in a query-like formulation (e.g., LAV/GAV mapping)
- homogeneous vs heterogeneous: do the alignments predicate on terms of the same type (e.g., classes are related only to classes, individuals to individuals, etc.) or we allow heterogeneity in the relationship?
- type of alignment: the semantics associated to an alignment. It can be subsumption, equivalence, disjointness, part-of or any user-specified relationship.
- Subsumption, atomic, homogeneous alignments are the building blocks to obtain richer alignments, and have a well defined semantics in every Description Logic.
Let's now introduce more formally ontology matching and mapping.
An atomic homogeneous matching is an alignment that carries a similarity degree [math]\displaystyle{ s\in [0,1] }[/math] , describing the similarity of two terms of the input ontologies [math]\displaystyle{ i }[/math] and [math]\displaystyle{ j }[/math] .
Matching can be either computed, by means of heuristic algorithms, or inferred from other matchings.
Formally we can say that, a matching is a quadruple [math]\displaystyle{ m=\langle id, t_{i}, t_{j}, s\rangle }[/math] , where [math]\displaystyle{ t_{i} }[/math] and [math]\displaystyle{ t_{j} }[/math] are homogeneous ontology terms, [math]\displaystyle{ s }[/math] is the similarity degree of [math]\displaystyle{ m }[/math] .
A (subsumption, homogeneous, atomic) mapping is defined as a pair [math]\displaystyle{ \mu=\langle t_{i}, t_{j}\rangle }[/math] , where [math]\displaystyle{ t_{i} }[/math] and [math]\displaystyle{ t_{j} }[/math] are homogeneous ontology terms.
- Given two ontologies [math]\displaystyle{ i=\langle C_{i}, R_{i}, I_{i}, A_{i}\rangle }[/math] and [math]\displaystyle{ j=\langle C_{j}, R_{j}, I_{j}, A_{j}\rangle }[/math] we can define different type of (inter-ontology) relationships among their terms.
2015a
- http://om2015.ontologymatching.org/
- QUOTE: Ontology matching is a key interoperability enabler for the Semantic Web, as well as a useful tactic in some classical data integration tasks dealing with the semantic heterogeneity problem. It takes the ontologies as input and determines as output an alignment, that is, a set of correspondences between the semantically related entities of those ontologies. These correspondences can be used for various tasks, such as ontology merging, data translation, query answering or navigation on the web of data. Thus, matching ontologies enables the knowledge and data expressed in the matched ontologies to interoperate.
2015b
- (Navigli, 2015) ⇒ Roberto Navigli. (2015). “Ontologies.” In: Reference Book Journal.
- QUOTE: This chapter is about ontologies, that is, knowledge models of a domain of interest. We introduce ontologies, view them from the perspective of several fields of knowledge, and present existing ontologies and the different tasks of ontology building, learning, matching, mapping and merging.
2014
- http://en.wikipedia.org/wiki/Ontology_alignment
- Ontology alignment, or ontology matching, is the process of determining correspondences between concepts. A set of correspondences is also called an alignment. The phrase takes on a slightly different meaning, in computer science, cognitive science or philosophy.
2013a
- (Pavel & Euzenat, 2013) ⇒ Pavel Shvaiko, and Jerome Euzenat. (2013). “Ontology Matching: State of the Art and Future Challenges.” In: IEEE Transactions on Knowledge and Data Engineering Journal, 25(1). doi:10.1109/TKDE.2011.253
- QUOTE: When several competing ontologies are used in different applications, most often these applications cannot immediately interoperate. …
...Overcoming semantic heterogeneity is typically achieved in two steps, namely: (i) matching entities to determine an alignment, i.e., a set of correspondences, and (ii) interpreting an alignment according to application needs, such as data translation or query answering. We focus only on the matching step. Ontology matching is a solution to the semantic heterogeneity problem. It finds correspondences between semantically related entities of ontologies.
- QUOTE: When several competing ontologies are used in different applications, most often these applications cannot immediately interoperate. …
2013b
- (Batet et al., 2013) ⇒ Montserrat Batet, David Sánchez, Aida Valls, and Karina Gibert. (2013). “Semantic Similarity Estimation from Multiple Ontologies.” In: Applied Intelligence Journal, 38(1). doi:10.1007/s10489-012-0355-y
- QUOTE: The estimation of semantic similarity between words is an important task in many language related applications.
2007a
- (Euzenat & Shvaiko, 2007) ⇒ Jérôme Euzenat, and Pavel Shvaiko. (2007). “Ontology Matching." Springer.
- QUOTE: Euzenat and Shvaiko’s book is devoted to ontology matching as a solution to the semantic heterogeneity problem faced by computer systems. Ontology matching aims at finding correspondences between semantically related entities of different ontologies.
2007b
- (Obitko, 2007) ⇒ Marek Obitko. (2007). “Translations Between Ontologies in Multi-agent Systems - Ontology Operations.” PhD Thesis, Czech Technical University
- QUOTE: It is possible that one application uses multiple ontologies, especially when using modular design of ontologies or when we need to integrate with systems that use other ontologies. In this case, some operations on ontologies may be needed in order to work with all of them. We will summarize some of these operations. The terminology in this areas is still not stable and different authors may use these terms in a bit shifted meaning, and so the terms may overlap, however, all of these operations are important for maintenance and integration of ontologies.
- Merge of ontologies (...)
- Mapping from one ontology to another one is expressing of the way how to translate statements from ontology to the other one. Often it means translation between concepts and relations. In the simplest case it is mapping from one concept of the first ontology to one concept of the second ontology. It is not always possible to do such one to one mapping. Some information can be lost in the mapping. This is permissible, however mapping may not introduce any inconsistencies.
- Alignment is a process of mapping between ontologies in both directions whereas it is possible to modify original ontologies so that suitable translation exists (i.e., without losing information during mapping). Thus it is possible to add new concepts and relations to ontologies that would form suitable equivalents for mapping. The specification of alignment is called articulation. Alignment, as well as mapping, may be partial only.
- Refinement is mapping from ontology A to another ontology B so that every concept of ontology A has equivalent in ontology B, however primitive concepts from ontology A may correspond to non-primitive (defined) concepts of ontology B. Refinement defines partial ordering of ontologies.
- Unification is aligning all of the concepts and relations in ontologies so that inference in one ontology can be mapped to inference in other ontology and vice versa. Unification is usually made as refinement of ontologies in both directions.
- Integration is a process of (...)
- QUOTE: It is possible that one application uses multiple ontologies, especially when using modular design of ontologies or when we need to integrate with systems that use other ontologies. In this case, some operations on ontologies may be needed in order to work with all of them. We will summarize some of these operations. The terminology in this areas is still not stable and different authors may use these terms in a bit shifted meaning, and so the terms may overlap, however, all of these operations are important for maintenance and integration of ontologies.
2006a
- (Choi et al., 2006) ⇒ Namyoun Choi, Il-Yeol Song, and Hyoil Han. (2006). “A Survey on Ontology Mapping.” In: ACM SIGMOD Record Journal, 35(3). doi:10.1145/1168092.1168097
- QUOTE: Ontology mapping is required for combining distributed and heterogeneous ontologies. Developing such ontology mapping has been a core issue of recent ontology research. … We believe this paper provides readers with a comprehensive understanding of ontology mapping and points to various research topics about the specific roles of ontology mapping. …
… We classify ontology mapping into the following three categories: 1) mapping between an integrated global ontology and local ontologies [3,4,1,7], 2) mapping between local ontologies [6,1,8,9,12,13,14], and 3) mapping on ontology merging and alignment. [15,16,17,18,19,20]
- QUOTE: Ontology mapping is required for combining distributed and heterogeneous ontologies. Developing such ontology mapping has been a core issue of recent ontology research. … We believe this paper provides readers with a comprehensive understanding of ontology mapping and points to various research topics about the specific roles of ontology mapping. …
2006b
- (Choi et al., 2006) ⇒ Namyoun Choi, Il-Yeol Song, and Hyoil Han. (2006). “A Survey on Ontology Mapping.” In: ACM SIGMOD Record Journal, 35(3). doi:10.1145/1168092.1168097
- QUOTE: … Ontology merging, integration, and alignment can be considered as an ontology reuse process. [2,24] Ontology merging is the process of generating a single, coherent ontology from two or more existing and different ontologies related to the same subject.26 A merged single coherent ontology includes information from all source ontologies but is more or less unchanged. The original ontologies have similar or overlapping domains but they are unique and not revisions of the same ontology. Ontology alignment is the task of creating links between two original ontologies. Ontology alignment is made if the sources become consistent with each other but are kept separate.15 Ontology alignment is made when they usually have complementary domains. Ontology integration is the process of generating a single ontology in one subject from two or more existing and different ontologies in different subjects. The different subjects of the different ontologies may be related. Some change is expected in a single integrated ontology.
2004
- (Giunchiglia et al., 2004) ⇒ Fausto Giunchiglia, Pavel Shvaiko, and Mikalai Yatskevich. (2004). “Smatch: An algorithm and an implementation of semantic matching.” In: Proceedings of the First European Semantic Web Symposium (ESWS 2004). doi:10.1007/b97867
- http://www.dit.unitn.it/~accord/Presentations/S-Match_ESWS.ppt
- It uses semantics for matching knowledge representation structures.
- It defines Match as a Function from two graph-line structures and produces mappings among the nodes that correspond semantically to each other.
- It is mainly based on the node labels
- It makes use of WordNet.
- Its graph structure is restricted to a tree.
2003
- (Kalfoglou & Schorlemmer, 2003) ⇒ Yannis Kalfoglou, and Marco Schorlemmer. (2003). “Ontology Mapping: the State of the Art.” In: The Knowledge Engineering Review. doi:10.1017/S0269888903000651
- QUOTE: A total ontology mapping from O1 = (S1,A1) to O2 = (S2,A2) is a morphism f : S1 → S2 of ontological signatures, such that, A2 |= f(A1), i.e., all interpretations that satisfy O2’s axioms also satisfy O1’s translated axioms. This makes an ontology mapping a theory morphism as it is usually defined in the field of algebraic specification (see, for instance, (Meseguer 1989)).