A TOOL FOR ORGANIZING WEB INFORMATION

The physical and logical differences among information sources on the Internet complicate information retrieval. For instance, data is no lo nger just simple text or tuples, but now includes objects and multimed ia. Data can also have varied and often arcane semantics. Sources have different policies, procedures, and conventions and are hosted by div erse platforms. Ontologies-models of concepts and their relationships- are a powerful way to organize query formulation and semantic reconcil iation in large distributed information environments. They can capture both the structure and semantics of information environments, so an o ntology-based search engine can handle both simple keyword-based queri es as well as complex queries on structured data. Ontology-based inter operation is especially good at dealing with inconsistent semantics. H owever, ontologies are difficult to construct. The Java Ontology Edito r (JOE) helps users build and browse ontologies. It also enables query formulation at several levels of abstraction. The authors discuss the use of JOE to develop a health care information system.