Heraclitus: Web Usage Driven Adaptation of the Semantic Web Alexander Mikroyannidis Babis Theodoulidis School of Informatics University of Manchester

Introduction The Semantic Web has emerged as a solution to the problem of organizing the immense information provided by the World Wide Web. However, a static Semantic Web can be of little use in the environment of the ever-transforming World Wide Web. The answer: Adaptation of the Semantic Web to the users’ needs and preferences .

The Semantic Web has emerged as a solution to the problem of organizing the immense information provided by the World Wide Web.

However, a static Semantic Web can be of little use in the environment of the ever-transforming World Wide Web.

The answer: Adaptation of the Semantic Web to the users’ needs and preferences .

Web Site Ontology (I) It is strongly related to the site topology . It is comprised of the thematic categories covered by the site’s pages. These categories are the concepts of the ontology. The concepts are organized in a hierarchy, representing an “is a” relationship. The concepts are instantiated in the web pages.

It is strongly related to the site topology .

It is comprised of the thematic categories covered by the site’s pages. These categories are the concepts of the ontology.

The concepts are organized in a hierarchy, representing an “is a” relationship.

The concepts are instantiated in the web pages.

Web Site Ontology (II)

Framework Principles Web Transformation Enhancement of usability for all visitors, including new ones Transparency Tactical vs. Strategic adaptations (Coenen et al 2000) Emphasis on the role of the webmaster Learning adaptation engine Adaptation of the physical and semantic structure: site ontology evolution

Web Transformation

Enhancement of usability for all visitors, including new ones

Transparency

Tactical vs. Strategic adaptations (Coenen et al 2000)

Emphasis on the role of the webmaster

Learning adaptation engine

Adaptation of the physical and semantic structure: site ontology evolution

Architecture Overview Pagesets : Sets of pages that are frequently accessed together throughout the same session Topology & Ontology Evolution Pagesets Classification Session Mining Preprocessing

Preprocessing Session identification approaches: Topology Content Temporal information

Session identification approaches:

Topology

Content

Temporal information

Session Mining Market Basket Analysis Incorporation of physical and semantic information: Web page location Web page classification

Market Basket Analysis

Incorporation of physical and semantic information:

Web page location

Web page classification

Topology & Ontology Evolution

Case Study University of Manchester School of Informatics web site ( www.informatics.manchester.ac.uk ) 2 , 500 web pages Approximately 4,000 hits/day 80% of the traffic is generated by undergraduate or postgraduate students

University of Manchester School of Informatics web site ( www.informatics.manchester.ac.uk )

2 , 500 web pages

Approximately 4,000 hits/day

80% of the traffic is generated by undergraduate or postgraduate students

Web Site Topology Evolution (I) Insertion of new shortcut links Highlighting of popular existing links

Insertion of new shortcut links

Highlighting of popular existing links

Web Site Topology Evolution (II)

Web Site Ontology Evolution (I) New associations between concepts e.g.: Research and Programmes concepts Reorganization of concepts’ hierarchy. C reation of new categories , changes in others e.g.: Transfer of Staff concept to the highest level of the ontology New categorization of web pages. Identification of multiple instances of concepts or multiple subconcepts e.g.: Job Vacancies page: categorized under Staff and Research

New associations between concepts

e.g.: Research and Programmes concepts

Reorganization of concepts’ hierarchy. C reation of new categories , changes in others

e.g.: Transfer of Staff concept to the highest level of the ontology

New categorization of web pages. Identification of multiple instances of concepts or multiple subconcepts

e.g.: Job Vacancies page: categorized under Staff and Research

Web Site Ontology Evolution (II)

Conclusions A web usage driven approach on the adaptation of the Semantic Web was introduced. The proposed framework targets both the physical and semantic aspects of the web. An architecture implementing the theoretical principles of the framework was proposed. Successful application of proposed methodology on a real web site.

A web usage driven approach on the adaptation of the Semantic Web was introduced. The proposed framework targets both the physical and semantic aspects of the web.

An architecture implementing the theoretical principles of the framework was proposed.

Successful application of proposed methodology on a real web site.

Future Work Automatic construction of the site ontology (e.g. agglomerative hierarchical clustering techniques) Meta-analysis of users’ access patterns Simultaneous adaptation of multiple web sites towards the development of the A daptive S emantic W eb

Automatic construction of the site ontology (e.g. agglomerative hierarchical clustering techniques)

Meta-analysis of users’ access patterns

Simultaneous adaptation of multiple web sites towards the development of the A daptive S emantic W eb

Thanks! To try out Heraclitus visit: http:// heraclitus.sourceforge.net