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CSA4080Adaptive Hypertext Systems II
Topic 7 Adaptation Techniques

• Dr. Christopher Staff
• Department of Computer Science AI
• University of Malta

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Aims and Objectives

• Review of stages in the adaptation process and
  adaptation techniques from CSA3080
• Adaptive navigation in Letizia, WebWatcher, and
  HyperContext

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Stages in the Adaptation Process

• Collect data about the user
• Process data to build/update user model
• Apply user model to provide the adaptation
• Last stage always fully automated in adaptive
  hypertext systems
• 1st and 2nd stages may require user intervention.
  Ideally, fully automated

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Stages in the adaptation process

• If user and system need to co-operate to achieve
  adaptivity, then it is called collaborative user
  modelling

From Brusilovsky96
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Problems Revisited

• Lost in HyperSpace
• Cognitive overload
• Complexity of the search space
• Search-browsing
• Static hypertext structure

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Generic solutions

• Adaptive Presentation
• Adaptive Navigation

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What can be adapted?

• A hypertext is a collection of nodes that are
  connected by links
• So what can be adapted?
• The node content and user interface - adaptive
  presentation
• The node organisation and hyperspace
  representations (e.g., index, map, overview) -
  adaptive navigation

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Adaptation Technologies
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Adaptive Navigation

• Adaptive Navigation-local reconnaissance is
  highly related to link annotation
• E.g., Letizia, WebWatcher, Personal WebWatcher,
  HyperContext
• Already talked about Personal WebWatcher in Topic
  4 (User Modelling) and CSA3080

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Adaptive Navigation

• Differences in ITS and generic approaches to
  adaptive navigation
• ITS aim is to transfer knowledge efficiently by
  guiding through a learning space
• Learned, ready to be learned, not ready to be
  learned
• Generic aim is to guide user through document
  space to relevant information (that is ideally
  also at the level of simplicity required by
  user!)
• Relevant, not relevant (what about related to
  interest X?)

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Adaptive Navigation

• Letizia
• Predicts a users interest as the user browses
  and suggests links to relevant document in the
  vicinity of the users current location
• User tends to traverse Web graph downwards, but
  relevant information may lie sideways
• Observes user behaviour to determine user
  interests (eg, skipping links, bookmarking...)
• Makes recommendations based on persistence of
  interest

lieberman95letizia.pdf
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Adaptive Navigation

• WebWatcher
• Guides users through a web site based on
  interaction with past users
• Users express a query and are guided to relevant
  documents
• Associates what users are interested in with
  documents that they mark as relevant
• Marks up links with terms used by users, and
  terms that occur in downstream documents

webwatcher.ijcai97.pdf
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Adaptive Navigation

• HyperContext
• Uses Information Retrieval-in-Context to guide
  users to information in hyperspace (up to 7 link
  traversals away)
• Once user has navigated to a location which
  probably contains information, can submit query
  to search context sphere
• With Adaptive Information Discovery, system
  generates query on behalf of user

HCTCh5.pdf
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Adaptive Presentation

• Already described MetaDocs Stretchtext
  functionality in CSA3080
• Approaches are generally intended to make the
  content more understandable to the user
• automatically including glossary explanations of
  terms unknown to the user
• removing extraneous information, or information
  known to the user
• showing information in format preferred by user...

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Summary

• Reminded ourselves of the problems that AHSs try
  to fix
• The adaptation process
• Adaptation technologies
• Examples of systems that incorporate adaptive
  navigation techniques