CSA3080:
Adaptive Hypertext Systems I
Lecture 12:
Adaptation Techniques I
Dr. Christopher Staff
Department of Computer Science & AI
University of Malta
CSA3080: Lecture 12
© 2003- Chris Staff
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University of Malta
Aims and Objectives
• We will look at stages in the adaptation process
and revisit the problems that AHS try to solve
(this lecture)
• We will look at two example AHSs: Personal
WebWatcher and MetaDoc, and some of the
research that’s happening at UoM (next lecture)
CSA3080: Lecture 12
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University of Malta
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
CSA3080: Lecture 12
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University of Malta
Stages in the adaptation process
• If user and system need to co-operate to achieve
adaptivity, then it is called collaborative user
modelling
Prov
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"Administrator"
Data about user
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User Model
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User
Adaptation Effect
From [Brusilovsky96]
CSA3080: Lecture 12
© 2003- Chris Staff
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University of Malta
Problems Revisited
•
•
•
•
•
Lost in HyperSpace
Cognitive overload
Complexity of the search space
Search-browsing
Static hypertext structure
CSA3080: Lecture 12
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University of Malta
Generic solutions
• Adaptive Presentation
• Adaptive Navigation
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Lost in HyperSpace
• Mark-up nodes to include link to landmark
which user knows about
• Show relationship between landmark node and
current node
• Reduce cognitive load on user
CSA3080: Lecture 12
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Cognitive overload
• Move (some) linking functions into AHS
system by, e.g., providing "See Also" links
• Automatic/dynamic linking
• Reduce number of outlinks by removing links to
non-relevant nodes
• Link recommendation services
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University of Malta
Complexity of the search space
• Removing links reduces the size of the search
space
• Recommending links assists the user in
deciding which links are likely to lead to
relevant information
• Automatically modifying content enables
readers to understand concepts at their level of
understanding
CSA3080: Lecture 12
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Complexity of the search space
• Learn from user access paths to re-organise
hyperspace
• Learn to associate user terminology with
document content
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Search-browsing
• Dynamic linking as a result of where user action
is combined with any stated query terms
• Recommend links (paths) to relevant documents
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Static hypertext structure
• Users can modify structure, and/or system can
learn from users
• What change(s) to hypertext systems would be
required? IR systems?
• Dynamic hypertext systems
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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 Presentation
• Anything to do with adapting how the presented
material is displayed to users
• Examples
– Adapting the UI (more to do with adaptive user
interfaces than adaptive hypertext per se)
– Modify data presentation so that it is presented in
user's preferred choice (e.g., charts)
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Adaptive Presentation
• More examples
– Automatically expand/collapse glossary items
according to user's level of expertise
– Provide "trails" through hyperspace according to
user's level of expertise
– Can be fairly complex - if user does not know
concept A, then unlikely to know concept B, so
concept B should also be automatically expanded
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Adaptive Presentation
• Adaptive presentation can be useful in any
adaptive hypertext system, but mostly used in
Intelligent Tutoring Systems
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Adaptive Navigation
• Focused around implicit link types in Webbased systems (ideally, link types are explicit)
• Identify as many implicit link types as
possible…
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Direct Guidance
• Mainly through "Next" buttons!
• Can include link/path recommendation
• What are the pre-requisites?
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Adaptive Sorting of Links
• Ordering links according to some ranking
scheme
• On what basis?
• On which of the implicit link types can this be
provided?
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Adaptive hiding of links
• Hide links which would lead to non-relevant
information
• What are the pre-requisites? In ITS systems? In
generic AHSs?
• Identify implicit link types which support
adaptive hiding
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Adaptive annotation of links
• Mark-up anchor text/link description to explain
the information at the destination of the link
• Description must be adaptive!
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University of Malta