1. Modelling Data-Intensive Web Sites with OntoWeaver Knowledge Media Institute The Open University Yuangui Lei, Enrico Motta, John Domingue {y.lei, e.motta, j.b.domingue}@open.ac.uk

2. Outline Motivation OntoWeaver Rationales Site View Modelling Presentation Modelling Customization Framework An Example Advantages and Limitations Conclusions

3. Motivation Data-intensive web sites –Time-consuming design process –Few re-usable components –Costly maintenance process Solutions –Model-based web modelling methodologies HDM, RMM, WebML, etc.

4. Customization Layer User Profiles User Model Customization Requirements Presentation Layer Presentation Styles Layouts Site View Layer Data Elements Navigational Elements KA Forms Query Forms Data Layer Databases Data Services Domain Model Current Research Practices

5. Open Issues Limited support for the specification of site views; –RMM, OOHDM, HDM-Lite –ARANEUS, WebML, OntoWebber, HERA Limited support for the specification of presentation styles and layouts; –Style sheets –Layout design Limited support for customization at design time as well as at run time; –The customization specification is intertwined with the site view layer –The aspects of customization are limited

6. OntoWeaver: an Ontology-Based Approach Goal: –to enable the process of designing ontology-based web applications to be carried out at the conceptual level Rationales –Employing the notion of ontology as the back-bone Site View Ontology Presentation Ontology Customization Framework –All aspects of a web site expressed declaratively Advantages –Low-cost route to data-driven web applications –All aspects of a web site amenable to reasoning Site Design Critiquing Customization

7. Customization Layer User Profiles User Model Customization Requirements Presentation Layer Presentation Styles Layouts Site View Layer Data Elements Navigational Elements KA Forms Query Forms Data Layer Databases Data Services Domain Model Domain Ontology Site View Ontology Presentation Ontology Customization Framework

8. OntoWeaver: an Ontology-Based Approach Goal: –to enable the process of designing ontology-based web applications to be carried out at the conceptual level Rationales –Employing the notion of ontology as the back-bone Site View Ontology Presentation Ontology Customization Framework –All aspects of a web site expressed declaratively Advantages –Low-cost route to data-driven web applications –All aspects of a web site amenable to reasoning Site Design Critiquing Customization

9. OntoWeaver Architecture OW Web Site Inference Engine Site Builder Presentation Specification Site View Specification Site Designer Site View & Presentation Ontologies User Profiles Domain Ontology Ontology Editor Customization Rule Base Site Customizer Online Page Builder User Ontology Customized View

10. Modelling the Site View Layer hasSubComponent hasSubResource Site Resource Component hasIndexResource hasComponent SubResource MetaData hasMetaData hasResource LinkItem hasOutput Output Input Command hasInput hasCommand hasLinkItem

11. Examples of the Site View Constructs KA component Input element Command Element Output Elements

12. Data Component Dynamic Output

13. Site View Constructs Summary Composite User Interface Constructs –Site, SiteResource, ResourceComponent Component Primitives: –DataComponent –KAComponent –SearchComponent Pre-defined services Atomic User Interface Constructs –Output, DynamicOutput, Command, Input Navigational Constructs –LinkItem, DynamicLinkItem, Parameter

14. Modelling the Presentation Layer Presentation Styles –Fonts, colours, etc –Template-based approach Templates: generic templates, widget templates, data component templates Presentation objects: attaching templates with site view components Layouts –Organization of site view components –Layout modelling Text Layout Component Layout Presentation Model –SitePresentation

15. Presentation Model SitePresentation Template hasPresentation hasTemplate hasLayout Presentation Layout PresentationTemplate ComponentURI hasTemplate hasComponentURI AreaLayout hasAreaLayout ComponentURI

16. Customization Framework Declarative Site Model –Site view specifications; –Site presentation specifications; –Site ontologies. User Ontology –A model to enable the recording of user profiles –Only very basic ontology is provided, typically this will be specialised for particular applications User Profiles –Information about end users in terms of user ontology. Customization Rules –Conditions –Customization Actions Jess Inference Engine

17. OntoWeaver Architecture OW Web Site Inference Engine Site Builder Presentation Specification Site View Specification Site Designer Site View & Presentation Ontologies User Profiles Domain Ontology Ontology Editor Customization Rule Base Site Customizer Online Page Builder User Ontology Customized View

18. Example: Building a Paper Review System Four types of users Authors –They browse conference information –They submit papers Reviewers –They get the papers assigned for review from the web site; –They submit their reviews to the web site; Program committee members –They browse review recommendations. Chair –Has access to everything, notifies authors, etc.

19. Design Process Domain Ontology Design: Site View Design: –Designing navigational structures –Composing user interfaces for web pages Presentation Design –Specifying visual appearance for user interface elements –Specify layout for user interface elements Customization Design: –Identifying potential audiences; –Creating different site models for different user groups; –Defining customization rules for individual users or groups;

20. OntoWeaver Site Designer

21. A General View

22. User Group Specified Customization

23. Rule-based Customization

24. Reviewers get extra links for obtaining assigned papers and submitting reviews; Two corresponding new web pages have been created; Customized web pages are generated on the fly when users whose role is Reviewer login onto the paper review system and make requests about web pages. A Customized View For Paper Reviewers

25. Advantages High level specification –The design can be made much simpler Automatic site generation through ontology mapping Customization support –The modular approach –The customization framework Site maintenance –Tools support for manual and semi-automatic maintenance

26. Limitations Focusing on data presentation, data acquisition, and data querying Remote web services are not considered Semantics of web pages are not explored

27. Conclusions OntoWeaver uses an ontology-driven approach to the design and development of data-intensive web sites. It provides a set of ontologies to support the modelling and specification of all aspects of data-intensive web applications. It provides a customization framework to allow the specification of customization requirements at a high level of abstraction. It provides a tool suite to support the design and development of data-intensive web istes.