Chapter 1 - The Semantic Web Vision
The World Wide Web is a great technological achievement that has strongly influenced most aspects
of the modern economies and societies. However, its current state is unsatisfactory because many
of the desired activities are not well supported by automated tools. For example, the main tool
for supporting information retrieval are keyword-based search engines. These tools, while indispensable,
have serious limitations in terms of recall, precision, and content across various Web Pages.
Most of today's Web content is meant for human consumption, with machines being able to caputre and
manipulate it only at the syntactic level. The central idea of the Semantic Web initiative is to make
the meaning of Web content machine accesible and processable. This enables the development of sophisticated
tools that can provide a much higher functionality in supporting human activities on the Web. The Semantic
Web relies on the combination of the following technologies:
Explicit metadata: they allow Web pages to carry theri meaning on their sleeves. For example, on a
professor's Web Page, metadata can identify name, position, affiliation, studies, publication etc.
Ontologies: they describe the main concepts of a domain and their relationships. For example, a
univerity ontology may contain concepts such as personnel, courses, classroms, and relationships such as
subclass information (all professors are university personnel).
Logical reasoning: it makes it possible to draw conclusions from combining (meta)data with