Web data indexing through external semantic-carrying annotations

Data annotations provide an effective means to link data from diverse data archives to a domain conceptualization, e.g., ontology, which then provides users with an integrated and uniform view for querying the data. Existing approaches typically use document annotation techniques that require authors to embed linkage information into their documents. This prevents true collaborative extensions of documents by annotations and conceptual views of multiple users on the same data. This paper presents the concepts and architecture underlying a data annotation framework that enables external annotations of remote data at different levels of granularity. Semantic-carrying annotations, based on a domain conceptualization model, allow multiple users to enrich the same data under different perspectives. XML and related techniques are used for managing, exchanging, and querying annotations and domain conceptualizations.