Ian Horrocks and Alan Rector University of Manchester

Ian Horrocks and Alan Rector University of Manchester, UK {arector|ihorrocks@cs. man. ac. uk}

Goals of the course

History of the Semantic Web “. . . a goal of the Web was that, if the interaction between person and hypertext could be so intuitive that the machine-readable information space gave an accurate representation of the state of people's thoughts, interactions, and work patterns, then machine analysiscould become a very powerful management tool, seeing patterns in our work and facilitating our working together through the typical problems which beset the management of large organizations. ”

Scientific American, May 2001:

Where we are Today: the Syntactic Web [Hendler & Miller 02]

The Syntactic Web is… [Goble 03]

Hard Work using the Syntactic Web… Rev. Alan M. Gates, Associate Rector of the Church of the Holy Spirit, Lake Forest, Illinois

Impossible (? ) using the Syntactic Web…

What is the Problem?

What information can we see…

What information can a machine see…

Solution: XML markup with “meaningful” tags?

Still the Machine only sees…

Need to Add “Semantics”

Ontology: Origins and History Ontology in Philosophy

Ontology in Linguistics Relates to activates Stands for

Classification: An Old Problem

Ontology in Computer Science

Example Ontology

Ontology Classified Logically

Where else are ontologies used?

Ontologies as Conceptual Lego “Hand which is anatomically normal”

User Interfaces using conceptual Lego • Fixation of open fracture of neck of left femur

So why is it hard?

Structure of an Ontology

Tools and Services

OWL as (Description) Logic

Ontologies as DL Knowledge Bases

Knowledge Base Semantics

Services as Reasoning

Results for Margherita Pizza

What it Means

DL Reasoning

Highly Optimised Implementation

Meanwhile related developments

Practicalities

Practicalities

Who are We?