A large amount of data produced by governmental organizations is accessible in the form of tables encoded as CSV files. Semantic table interpretation (STI) strives to transform them into linked data in order to make them more useful. As significant portion of the tabular data is of statistical nature, and therefore comprises predominantly of numeric values, it is paramount to possess effective means for interpreting relations between the entities and their numeric properties as captured in the tables. As the current general-purpose STI tools infer the annotations of the columns almost exclusively from numeric objects of RDF triples already present in the linked data knowledge bases, they are unable to handle unknown input values. This leaves them with weak evidence for their suggestions. On the other hand, known techniques focusing on the numeric values also have their downsides. Either their background knowledge representation is built in a top-down manner from general knowledge bases, which do not reflect the domain of input and in turn do not contain the values in a recognizable form. Or they do not make use of context provided by the general STI tools. This causes them to mismatch annotations of columns consisting from similar values, but of entirely different meaning. This thesis addresses the...

The current World Wide Web is a web of pages. Users have to guess possible keywords that might lead through search engines to the pages that contain information of interest and browse hundreds or even thousands of the returned pages in order to obtain what they want. This frustrating problem motivates an approach to turn the web of pages into a web of knowledge, so that web users can query the information of interest directly. This dissertation provides a step in this direction and a way to partially overcome the challenges. Specifically, this dissertation shows how to turn machine-generated web pages like those on the hidden web into semantic web pages for the web of knowledge. We design and develop three systems to address the challenge of turning the web pages into web-of-knowledge pages: TISP (Table Interpretation for Sibling Pages), TISP++, and FOCIH (Form-based Ontology Creation and Information Harvesting). TISP can automatically interpret hidden-web tables. Given interpreted tables, TISP++ can generate ontologies and semantically annotate the information present in the interpreted tables automatically. This way, we can offer a way to make the hidden information publicly accessible. We also provide users with a way where they can generate personalized ontologies. FOCIH provides users with an interface with which they can provide their own view by creating a form that specifies the information they want. Based on the form, FOCIH can generate user-specific ontologies, and based on patterns in machine-generated pages, FOCIH can harvest information and annotate these pages with respect to the generated ontology. Users can directly query on the annotated information. With these contributions, this dissertation serves as a foundational pillar for turning the current web of pages into a web of knowledge.