Ontologies

An ontology is a formal description of knowledge as a set of concepts within a domain and the relationships that hold between them. It ensures a common understanding of information and makes explicit domain assumptions thus allowing organizations to make better sense of their data.

What is Ontology?

An ontology is a formal description of knowledge as a set of concepts within a domain and the relationships that hold between them. To enable such a description, we need to formally specify components such as individuals (instances of objects), classes, attributes and relations as well as restrictions, rules and axioms. As a result, ontologies do not only introduce a sharable and reusable knowledge representation but can also add new knowledge about the domain.

The ontology data model can be applied to a set of individual facts to create a knowledge graph – a collection of entities, where the types and the relationships between them are expressed by nodes and edges between these nodes, By describing the structure of the knowledge in a domain, the ontology sets the stage for the knowledge graph to capture the data in it.

There are, of course, other methods that use formal specifications for knowledge representation such as vocabularies, taxonomies, thesauri, topic maps and logical models. However, unlike taxonomies or relational database schemas, for example, ontologies express relationships and enable users to link multiple concepts to other concepts in a variety of ways.

As one of the building blocks of Semantic Technology, ontologies are part of the W3C standards stack for the Semantic Web. They provide users with the necessary structure to link one piece of information to other pieces of information on the Web of Linked Data. Because they are used to specify common modeling representations of data from distributed and heterogeneous systems and databases, ontologies enable database interoperability, cross-database search and smooth knowledge management.

Ontologies for Better Data Management

Some of the major characteristics of ontologies are that they ensure a common understanding of information and that they make explicit domain assumptions. As a result, the interconnectedness and interoperability of the model make it invaluable for addressing the challenges of accessing and querying data in large organizations. Also, by improving metadata and provenance, and thus allowing organizations to make better sense of their data, ontologies enhance data quality.