Using Relationships Between Ontologies To Enhance Ontology Search

Using semantic web search engines, such as Watson, Swoogle or Sindice, to find ontologies is a complex process as it is often an exploratory activity. It generally requires formulating multiple queries, browsing many pages of results and assessing the returned ontologies against each other to obtain a relevant and adequate subset of ontologies for the intended use. Our hypothesis is that part of the difficulty related to searching ontologies comes from the lack of structure in the search results, where ontologies that are implicitly related to each other are presented as disconnected and shown on different result pages. In a previous work, to overcome this situation, we devised a software framework, Kannel, that detects and makes explicit relationships between ontologies in large ontology repositories. In this paper, we present a study that compares the use of the Watson ontology search engine with the use of its extension, Watson+Kannel, that provides explicit information regarding the various types of relationships between the result ontologies. We evaluate the benefit of Watson+Kannel by measuring through various indicators how these explicit relationships between ontologies are used to improve the user’s efficiency in ontology search, thus validating our hypothesis.