Therefore, we propose an enhanced model of the Semantic Web to characterize both the content and the context of Semantic Web data. Based on this model, we have harvested a significant and less biased sample set of Semantic Web data from the Web to measure the global properties of the Semantic Web. Moreover, we build a novel search and navigation model to characterize the unique Semantic Web data access behaviors and then develop a Semantic Web search engine as enabling tool. Finally, we investigate two important technologies for evaluating the quality of Semantic Web data: (i) a rational ranking algorithm which orders the popularity of Semantic Web documents and terms using our search and navigation model, and (ii) a new level of granularity, RDF molecule, to support lossless decomposition of an RDF graph and finding its (partial) supportive evidences on the Semantic Web. This dissertation systematically investigates the Web aspect of the Semantic Web. Its primary contributions are the enhanced conceptual model of the Semantic Web, the novel Semantic Web search and navigation model, and the Semantic Web search engine. ]]>