What is SWOOGLE?
Swoogle is a Semantic Web Search and Metadata Engine and a crawler-based indexing and retrieval system for the Semantic Web. It extracts metadata for each discovered document, and computes relations between documents. Discovered documents are also indexed by an information retrieval system which can use either character N-Gram or URIrefs as keywords to find relevant documents and to compute the similarity among a set of documents. One of the interesting properties we compute is rank, a measure of the importance of a Semantic Web document.
Swoogle’s architecture can be broken into four major components: SWD discovery, metadata creation, data analysis, and interface. This architecture is data centric and extensible: components work independently and interact with one another through a database.
The Semantic Web Document (SWD) discovery component discovers potential SWDs throughout the Web and keeps up-to-date information about SWDs. The size of the Semantic Web is measured by the number of discovered SWDs. The Semantic Web’s content can be divided into two categories
I. Program generated instance data
II. Hand crafted ontologies
The first category is the larger and includes FOAF personal profiles, RSS news feeds, RDF metadata embedded in PDF files Creative Commons’ copyright statements, and assertions extracted from structured data sources such as WordNet and the CIA fact book. The metadata creation component caches a snapshot of a SWD and generates objective metadata about SWDs at both the syntax level and the semantic level. The data analysis component uses the cached SWDs and the created metadata to derive analytical reports, such as classification of SWOs and SWDBs, rank of SWDs, and the IR index of SWDs. The interface component focuses on providing data service to the Semantic Web community.
Navigating and Ranking SWDs and SWTs
Since semantic web data is highly distributed, facilitating data access and assessing data quality are challenging. For example, how can users find relevant domain ontologies and then choose a popular and trustworthy one for use? Swoogle’s services provide agents with the semantic web search and navigation framework model. This model is defined by the links and paths within the Semantic Web and differs from conventional web navigation model in that it considers the interactions between two levels of abstraction: the RDF graph and the web of SWDs.
Swoogle also provides a customizable algorithm inspired by Google’s PageRank algorithm but adapted to the semantics and use patterns found in semantic web documents.
