Semantic WebBY: 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

<item>Club</item>

VS

<item rdf:about="http://dbpedia.org/page/Club">Club</item>

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)

– <item>Enzyme</item>

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