Thing Ontologies for the Semantic Web of Things

The Web of Things (WoT) Thing Description (TD) of W3C is a JSON template representation of Thing properties (e.g. purpose, data types, and operations). In recent work, we proposed that Things can be treated as Web services, and be described using OpenAPI. OpenAPI specification provides a method for documenting RESTful services so that a user or another service can comprehend their purpose and reuse them in applications. The resulting descriptions by either approach (i.e. W3C and OpenAPI) can be semantically extended using ontologies or can be mapped to an ontology to allow a machine to better understand the inherent meaning of Thing descriptions and interact with them. Then, Things can be discovered (i.e. queried) using Semantic Web query languages (e.g. SPARQL) and checked by reasoners (e.g. Pellet) for consistency or, to infer new properties. In this work, both approaches are discussed and compared in terms of the completeness of their representation.