Mark J. Weal, Gareth V. Hughes, David E. Millard, Luc Moreau

Open Hypermedia as a Navigational Interface to

Ontological Information Spaces

OverviewOntological Information

Systems model information very precisely

But can be very difficult for People to access and understand

Ontologies

• The word “Ontology” denotes the science or study of being

• In Agent Systems an Ontology comprises a vocabulary describing a certain domain

• Ontologies are designed artefacts• Ontologies are a shared understanding of some

domain• Agent-based information management systems are

designed to manipulate ontological information spaces

SoFAR

• Southampton Framework for Agent Research• In SoFAR, ontologies are organised as a hierarchy based on single inheritance• Terms describe a structure• Predicates describe a relationship between terms

<term name="Person" extends="Entity">

<field type="String" name="title"/>

<field type="String" name="personal"/>

<field type="String" name="family"/>

</term>

Querying Ontologies

• SoFAR’s query language is based on pattern-matching and requires adding variables and constraints to ontological definitions :

Person("Dr"; "Luc"; "Moreau")Person(?String; "Luc"; ?String)

• Querying terms looks up data• Querying predicates asks a question

InGroup(Person(?String; "Luc"; ?String); ?Group)

The Interface• Composing queries requires an in depth understanding

of the ontology• Keyword search ignores inherent structure of the

information space• Open Hypermedia – link navigation initiates complex

queries in the background. This separates :– the graphical interface– the process of querying– the process of link generation– the ontological information space

FOHM

• The Fundamental Open Hypertext Model• Based on the Open Hypermedia Protocol (OHP)

developed by the Open Hypermedia Systems Working Group (OHSWG)

• Extends OHP data model to represent several domains of hypermedia

• SoFAR FOHM Server Agent provides Open Hypermedia Services to SoFAR agents

Navigational Structure

FOHM and Ontologies

The Dynamic C.V.

• Set of Agents that have access to information about our group – publications agent– ECS database agent (phone numbers, group, etc.)– Seminars agent (internal seminars by group members)

• Dynamic C.V. is an agent with a web user interface that queries these agents to build a Curriculum Vitae

• Web Agent sends request to Dynamic C.V.

• User request Info on Person

• C.V. Finds appropriate Query Recipe in LinkServer

• Uses the destinations as queries to the agent cloud

• Converts the resultant terms into XML and passes them to the Annotator

• Annotator searches for query recipes on those terms in the LinkServer

• XML marked up with references to the cache are transformed by XSL and passed back to the browser

• Query recipes are stored in the cache

The Linkbases

• FOHM Associations link terms to potential queries (predicates) over the ontologies in the system :

Src : Person(?String; ?String; ?String)Dest1 : HasEmail(?Person; ?Email)Dest2 : HasPhone(?Person; ?Phone)

• The destinations are used to build each dynamic ‘page’• The Annotator searches for other recipes with the

destinations as sources

The ‘Query Recipes’

Person HasOffice

HasTelephone

InGroup

IsUserCreates

Seminar

The ‘Query Recipes’

Person HasOffice

HasTelephone

InGroup

IsUserCreates

Seminar

General C.V. of a person

The ‘Query Recipes’

Person HasOffice

HasTelephone

InGroup

IsUserCreates

Seminar

A Person’s publications

The ‘Query Recipes’

Person HasOffice

HasTelephone

InGroup

IsUserCreates

Seminar

A person’s seminars

What are Wendy’s publications?

Who else wrote this paper?

Who is Danius?

Who else has this phone number?

Conclusions

• Separation of Concerns– Ontologies for Information– Hypermedia for Navigation

• Static to Dynamic Documents• Hides complex ontological models• Alternative linkbases• FOHM supports different modes of interaction• New query recipes can be easily added