Ontological Hypertext

1
Ontological Hypertext

• Gary Wills

2
Overview

• Open Hypertext
• Hypertext Design
• Ontologies
• Ontological Hypertext Design

3
Open Hypertext

• Fountain et al in 1990 describe an open
  hypermedia system as one
• which does not impose any mark-up upon the data
  that will prevent the data from being accessible
  to other processes that do not belong to the
  system.
• In which there is a separation of links from data
  objects.
• Links are first class objects.

4
Linkbases

• The link information is held in link databases
  (linkbases).
• A linkbase holds all the information referring to
  a particular set of links,
• linkbases were commonly flat text files with one
  record per link, now represented XML
• linkbases containing the source and destination
  information.
• Link description, and any other information
  required.
• More than one linkbase can be applied to provided
  different views.

5
Types of Links

• Specific Links
• From a specific point in a specific document.

Specific
S
D
6
Types of Links

• Local Links
• From any matching point in a specific document.

Local
S
D
7
Types of Links

• Generic Links
• From any matching point in any document

Generic
S
D
8
Types of Links

• Specific, Local and Generic links
• As they are not embedded as mark-up there can be
  more than one destination returned
• Links have traditionally been explicitly authored
  and stored
• To implement an intended navigational order

9
Distributed Link Services

• Applying open hypermedia principles to the Web.
• the Distributed Link Service.

10
Traditional linking

• The text can be become over linked.
• As links are added at run time
• Failure of link integrator.
• We need to decrease the reliance on authored
  links
• More sophisticated content recognition
• TF-IDF
• QUIC
• Recommender Systems
• Adaptive Hypermedia

11
Overview

• Open Hypertext
• Hypertext Design
• Ontologies
• Ontological Hypertext Design

12
Hypertext Design

• The objective of hypermedia design models is to
  produce a well-organised web site.
• The organisation is undertaken at the level of a
  particular building-block an abstract data unit
  which may match a frame, paragraph or region on a
  Web page.
• The resulting applications are largely built to
  present/publish the data, but not to manage the
  content.

13
Hypertext Design

• Many of the hypertext models take a simple
  layered approach
• catalogue of assets
• A lack of cement connecting the layers and the
  means of mapping between the different layers
  when addressing the content

14
Hypertext Design

• The increasing sophistication of these models
  allows the designer to deal with interaction and
  personalisation, but precludes one of the basic
  features of hypertext the text itself.
• Not the content unit but the concepts
• Gap between organisation and origination of
  material when using generic links

15
Hypertext Design

• Many models restrict user navigation by use of
  buttons or links contained in tool or sidebars.
• However, usability studies by Nielsen show
  when they arrive on a page, users ignore
  navigation bars and other global design elements
  instead they look only at the content area of the
  page .

16
Overview

• Open Hypertext
• Hypertext Design
• Ontologies
• Ontological Hypertext Design

17
Ontologies
Ontology
Dictionary
Formal Logic
Specification of Conceptualization
Abstract Relations
Definitions of Terms

• Ontologies form the backbone of the knowledge
  interpretation
• Hypertext aims to improve familiar textual
  communications
• Semantic Web machine processed semantics
• Knowledge exchange and reuse

18
Ontologies

• In Knowledge Management an ontology is a
  specification of a conceptualization Gruber
• defines the vocabulary with which queries and
  assertions are exchanged among agents
• Ontologies sets out the entities that we are
  interested in and the relationships that bind
  them together.
• This is intended to be a pragmatic definition
• An ontology is a tool whose quality is entirely
  dependent on its usefulness.

19
Ontologies

• An immediate Web application of ontologies is in
  searching
• otherwise a purely syntactic activity matching
  patterns of letters.
• Ontology-augmented searches can determine that a
  page about yetis is relevant to a search for
  monsters,
• Formal statements in a standard Web language
  refer directly to concepts in the ontologies and
  to some content on the Web,
• a-b-o-m-i-n-a-b-l-e- -s-n-o-w-m-a-n in a
  particular document refers to a Yeti.

20
Ontologies

• An ontology is a formal model
• that allow reasoning about concepts and objects
  that appear in the real world
• that allow reasoning (crucially) about the
  complex relationships between them
• Normal hypertext design practice analyses the
  texts in order to devise a suitable
  infrastructure.
• Ontologically-motivated hypertexts derive the
  structuring of their components from the
  relationships between objects in the real world.

21
Overview

• Open Hypertext
• Hypertext Design
• Ontologies
• Ontological Hypertext Design

22
Ontological linking

• Ontological linking potentially offers
• agree collection of significant concepts,
  expressed as an agreed vocabulary in a given
  natural language, modelled together with agreed
  inter-relationships.
• linking through simple lexical matching had
  serious limitations due to the uncontrolled
  method of adding generic links

23
Ontological linking

• Ontological linking potentially offers
• providing an understanding of what can be linked
• subject key terms, foreign terms, named entities,
  general concepts.
• with what kinds of things should be linked in
  order to achieve a particular goal
• glossary explanation, tutorial support, related
  information

24
Building Ontological hypertexts

• Ontologies are used to define the entities of
  interest
• different perspectives on these entities will
  result in different ontology's.
• for example subject ontology, community
  ontology, argumentation ontology
• result in different linked structures that are
  suitable for entirely different purposes

25
COHSE project (Conceptual OHS Environment)

• COHSE is ontological hypermedia system
• combining an existing open hypermedia link
  service with an ontological reasoning service.
• to provide linking on the concepts that appear in
  Web pages, as opposed to linking on simple
  uninterpretted text fragments.
• COHSE used a standard Web browser controlled by
  an adapted link service which in turn used
  independent services to manipulate the exposed
  DOM of the Web page, resulting in the effect of
  ontologically-controlled hypertext.

26
COHSE

• The ontologies are internally represented using
  DAMLOIL and queries are satisfied using the FaCT
  reasoner

27
Ontoportal

• A system designed to create portals onto weakly
  linked resources.
• The portal allows a weakly linked web to be
  enriched through the meta-layer provided by the
  portal

28
T-portal

• It allows users to benefit from web-based
  teaching and learning resources by linking
  related but not previously linked resources.

29
Writing in the Context of Knowledge (WiCK)
interrelationships between concepts embedded in
the documents, and exposing these concepts whilst
the document is being written.
authors with appropriate knowledge for
constructing texts
30
WiCKED

• The authoring environment is supported by an
  enhanced knowledge structure with which it
  interacts to provide at authoring time various
  services including
• content generation for automatic text creation,
• annotation to keep explicit reference to the
  source,
• concept browsing to explore ontological
  relationships,
• semantic queries over a repository of
  semantically annotated and indexed documents,
• document management for usual services with a
  document store.
• WiCKed is based on Triplestore the AKT 3store
  RDF knowledge base.

31
WiCKED Example

• For example let us examine a research proposal
  for Quai Interactive Document System (QuIDS).
• Research Ontology, Subject Ontology, Project
  Ontology, Document ontology
• provide a summary of the results and conclusions
  of recent work in the technological/scientific
  area which is covered by the research proposal.
• identify the overall aims of the project and
  the individual measurable objectives against
  which you would wish the outcome of the work to
  be assessed

32
WiCKED

• A document authoring environment that takes
  advantage of some semantic web technologies to
  enable knowledge reuse while creating new
  documents.
• The consistency and coherence of resulting
  documents are improved because they explicitly
  assimilate and link to relevant background
  knowledge.

Text editor
Knowledge fragments from KB
33
WiCK
34
Conclusions

• Open hypertext is well established
• Versatile linking structures
• Explicitly authored.
• Hypertext Design
• Orthogonal processes (no cement)
• Ontologies
• Agreed common language
• Human and machine readable.

35
Conclusions

• Ontological Hypertext
• can overcome the problem of prolific linking
• providing an understanding of what can and should
  be linked in order to achieve a particular goal.
• Free Linking

36
Acknowledgement

• Les Carr
• Simon Kempa
• Timothy Miles-Board
• Arouna Woukeu