Semantic Web BY: Josh Rachner and Julio Pena

What is the Semantic Web? The semantic web is a part of the world wide web that allows data to be better represented by its actual meaning and content and provides access to collections of information that are in machine-readable formats “Most of the Web's content today is designed for humans to read, not for computer programs to manipulate meaningfully.” Berners-Lee, T, Hendler, J & Lassila, O ‘The semantic web’, Scientific American, May 2001

Why use Semantic Web? Make data machine-readable Describe and infer about content Provide ways to share and link data Supply better search results

Evolution of the Web

Current Classifying Methods Meta tags XHTML/XML tags Actual Web content What's the problem here?

Example Club VS Club

Link to Club Object

Critics of Semantic Web Better for specialized organizations and internal within companies It's an idea that people have not come to terms with Privacy and censorship of data Redundancy of information

Components of Semantic Web eXtensible Markup Language (XML) – Enzyme Resource Description Framework (RDF) – Uses N-triples (e.g. enzyme IS a protein) Ontologies – Hierarchies of concepts Rules for inference – If A = B, and B = C, then A = C

Using OWL to Model Biological Knowledge Robert Stevens, Mikel Aranguen, Katy Wolstencroft, Ulrike Sattler, Nick Drummond, Matthew Horridge, Alan Rector

Web Ontology Language (OWL) OWL is a representative language; its main use is to make it easier for web content to be read by machines rather than just humans There are three sublanguages of OWL: – OWL Lite – classification hierarchy w/ simple constraints – OWL DL – more expressive but is also limited – OWL Full – allows maximum expressiveness

Phosphatase Ontology Defined in terms of p-domain composition Tyrosine phosphatase → Protein phosphatase → Phosphatase Example:  1 immunoglobin p-domain  2 protein tyrosine phospatase p-domains

Why OWL Description Logic Description of classes and subclasses Restriction to unary predicates and binary predicates - contains Distinction between relationships of classes Full boolean operators Open world

Overview Semantic web is a possible solution for relating data and finding more meaning to information It is a new concept but could really change the world wide web and how information is shared Many organizations and companies currently use semantic web for research and commercial purposes