Adaptive Hypermedia

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Adaptive Hypermedia

• Dr. Alexandra Cristea
• a.i.cristea_at_tue.nl
• http//wwwis.win.tue.nl/alex/

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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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1. Adaptive Hypermedia of the Past, Present and
Future

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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1. Adaptive Hypermedia of the Past, Present and
Future

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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What is Adaptive Hypermedia?

• Hypermedia
• different media types used in a single
  application (text, images, sound, video, )
• non-linear structure with navigation through
  hyper-links
• Adaptive
• application forms a model of the context in which
  it is used (user, place, time, device, etc.)
• application adapts to that context (can show
  different information, different media, different
  links, etc.)
• adaptation and user modeling interact with each
  other (or else we say the application is
  adaptable, not adaptive)

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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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The need for personalization
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Why Adaptive Hypermedia?

• Problems with (non-adaptive) hypermedia
• using hypermedia is difficult because the author
  did not anticipate the path the end-user follows
• using hypermedia is also difficult because it is
  easy to get lost in hyperspace
• authoring hypermedia is difficult because of the
  navigational freedom of end-users
• Solutions through adaptive hypermedia
• compensate for unexpected comprehension problems
  due to the chosen navigation paths
• warn users before following links that lead to
  problematic navigation paths
• offer orientation support using adaptive overviews

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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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Application Areas

• Educational hypermedia systems
• on-line course text, with on-line multiple-choice
  or other machine-interpretable tests
• On-line information systems
• information kiosk, documentation systems,
  encyclopedias, etc.
• On-line help systems
• context-sensitive help, (think of Clippy)
• Information retrieval and filtering
• adaptive recommender systems
• etc.

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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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Traditional Hypermedia
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Adaptation on Trad. Hypermedia
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Adaptation on Trad. Hypermedia
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Adaptation on Trad. Hypermedia
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Adaptation on Trad. Hypermedia
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What can be adapted? classical views

• Adaptive presentation
• change which information is shown
• change how that information is shown
• Adaptive navigation support
• change which links are shown
• change how these links are shown
• change the link destinations

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Adaptive Presentation
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Adaptive Navigation Support
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Example from 2L690

• Before reading about Xanadu the URL page shows
• In Xanadu (a fully distributed hypertext
  system, developed by Ted Nelson at Brown
  University, from 1965 on) there was only one
  protocol, so that part could be missing.
• After reading about Xanadu this becomes
• In Xanadu there was only one protocol, so that
  part could be missing.

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Example from Interbook
4

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2
v
1
1. Concept role 2. Current concept state
3. Current section state 4. Linked sections state
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Adaptive vs. adaptable
personalized
adaptive
adaptable
System-tuned
User-tuned
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Gerhard Fischer 1 HFA Lecture, OZCHI2000
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A Comparison between Adaptive and Adaptable
Systems
Gerhard Fischer 1 HFA Lecture, OZCHI2000
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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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Adapt to what?

• User ? user model (UM)
• Goals ? goal model (GM)
• Domain ? domain model (DM)
• Media ? presentation model (PM)

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Adapt to what?

• Goal local and global
• Goal is the answer to the question Why is the
  user using the hypermedia system and what does
  the user actually want to achieve?
• Goals can be local or global. Local goals may
  changed quite often. For example, the
  problem-solving goal is a local one, which
  changes from one educational problem to another
  several times within a session. Global goal can
  be the users learning goal.

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Adapt to what?
Domain model properties
Adapt to
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Adapt to what?

• Context / environment
• aspects of the users environment, like browsing
  device, window size, network bandwidth,
  processing power, etc.

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User modelling is always about guessing
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Classical User Model Overlay UM

• users knowledge subset of experts knowledge
• goal of tutoring to enlarge this subset.
• This model is particularly appropriate when the
  (teaching) material can be represented as a
  prerequisite hierarchy.

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Adapt to what (else)?

• Knowledge about the subject domain (and possibly
  also knowledge about the system)
• Preferences
• Interests
• Learning or cognitive styles
• Background profession, language, prospect,
  capabilities
• Experience
• Navigation history

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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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Classic loop (Brusilovsky, 01)
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AM adaptation rules

• Purpose is to describe how an AHS
• updates the user model
• generates adaptation (presentation
  specifications)
• Description uses condition-action rules
• under which condition is the rule executed
• which (user model) concept attribute is updated
• does this update trigger other rules?

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Adaptive Hypermedia (Brusilovsky)

• 3 criteria It should be a hypermedia system,
  it should have a user model, and it should be
  able to apply hypermedia using this model.

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Web-based Adaptive Hypermedia

• Client-server architecture using HTTP
• only page accesses are registered (not scrolling,
  within-page scripting code or animations, etc.)
• following a link activates a server-side program
  (CGI-script, Java Servlet, )
• the program uses the link URL and the user model
  to determine which page to return
• the program performs content and link adaptation
  based on the user model (and some adaptation
  rules)
• the program updates the user model taking into
  account that the user will read the presented
  information

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Index

• Definitions
• Why AH?
• Application areas
• What to adapt?
• Adapt to what?
• How to adapt - past?
• New solutions

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New, dynamic view of AH
text
Bits pieces
link

• Generation
• only text
• only link
• text link

text
link
text
link
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Solutions

• Standardisation
• Authoring

New theoretical frameworks needed!
New implementations!
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Current standards

• Systems architecture
• Runtime environment
• Learning objects and Learning object metadata
• Learners profile and performance information
• Content sequencing and behaviour

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Main organizations

• IEEE LTSC (Learning Technology Standards
  Committee, http//ltsc.ieee.or)
• European CEN/ISSS Learning Technologies
  Workshop, www.cenorm.be/isss/Workshop/lt/
• The IMS (Instructional Management Systems, Global
  Learning Consortium Inc, www.imsproject.org)
• The US ADLnet (Advanced Distributed Learning
  Network, www.adlnet.org)
• CETIS (Centre for Educational Technology
  Interoperability Standards) http//www.cetis.ac.u
  k/
• AICC (Aviation Industry CBT Committee) http//www
  .aicc.org
• ARIADNE (Alliance of Remote Instructional
  Authoring and Distribution Networks for
  Europe) http//ariadne.unil.ch/
• Edutella (http//edutella.jxta.org)

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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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Authoring AHS

• content alternatives, adaptation techniques
  whole user-interaction mechanism design
• complicated heavy task gt they require help,
  guidelines automation facilities.
• for AHS to spread widely gt facilitate author
  work
• (Open Learning Repositories)

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Authoring standardization

• Formalization attempts
• standardising the whole procedure
• Research on a systematic base
• clear explicit models for adaptive authoring

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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Adaptive navigation presentation
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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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LAOS

• What is LAOS?
• Concept based adaptation
• LAOS components
• Why LAOS?
• LAOS authoring steps
• Future directions

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What is LAOS ?

• a generalized model for generic adaptive
  hypermedia authoring
• based on the AHAM model
• based on concept maps
• http//wwwis.win.tue.nl/alex/HTML/Minerva/papers/
  WWW03-cristea-mooij.doc
• http//www.ifets.info/journals/7_4/7.pdf

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General motivation for layer distributed
information

• Flexibility
• Expressivity (semantics also meta-data)
• Reusability
• Non-redundancy
• Cooperation
• Inter-operability
• Standardization

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LAOS components

• domain model (DM),
• goal and constraints model (GM),
• user model (UM),
• adaptation model (AM) and
• presentation model (PM)

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DM
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GM
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Catch-phrases

• write once, deliver many
• Exchange not only ingredients, but also the
  recipe

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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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Overview LAG

• What is LAG
• LAG components
• Why LAG?
• New adaptation rules
• Adaptation strategies

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What is LAG ?

• a generalized adaptation model for generic
  adaptive hypermedia authoring
• First paper http//wwwis.win.tue.nl/alex/Confere
  nces/02/AH02/calvi-cristea-final-w-header-ah2002.p
  df
• Second (referring) paper http//wwwis.win.tue.nl/
  alex/Conferences/02/ELEARN02/Cristea-Adaptation-A
  daptability.pdf
• Third paper http//wwwis.win.tue.nl/alex/HTML/Mi
  nerva/papers/UM03-cristea-calvi-accepted.doc

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Adaptation granularity

• lowest level direct adaptation techniques
• adaptive navigation support adaptive
  presentation (Brusilovsky 1996), implem. AHA!
  expressed in AHAM syntax
• techniques usually based on threshold
  computations of variable-value pairs.
• medium level goal / domain-oriented
  adaptation techniques
• based on a higher level language that embraces
  primitive low level adaptation techniques
  (wrapper)
• new techniques adaptation language (Calvi
  Cristea 2002),
• high level adaptation strategies
• wrapping layers above
• goal-oriented

Adaptation Assembly language
Adaptation Programming language
Adaptation Function calls
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Motivation LAG

• Authoring with different complexity degrees
  (beginner authors!! vs. advanced)
• Reuse at each level
• Better semantics
• standardization

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New adaptation rulesLAG Adaptation Language
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Adaptation Programming language

• level rule
• IF ENOUGH(ltPREREQUISITESgt) THENltACTIONgt
• temporal rule
• WHILE ltCONDITIONgt DO ltACTIONgt
• repetition rule
• FOR lti1..ngt DO ltACTIONgt
• interruption command
• BREAK ltACTIONgt
• generalization command
• GENERALIZE (COND, COND1, , CONDn)
• specialization command
• SPECIALIZE (COND, COND1, , CONDn)

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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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System demo

• MOT
• http//localhost//MOT03/
• http//wwwis.win.tue.nl/MOT03/TeachersSite-html/en
  ter.html
• AHA!
• http//localhost8080/ahamot/author/
• http//wwwis.win.tue.nl8090/ahamot/author/

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Outline

• Adaptive Hypermedia of the Past, Present and
  Future
• Authoring for Adaptive Hypermedia
• AH Authoring reference architecture LAOS
• A closer look on adaptation design LAG
• Authoring system MOT
• Delivery System AHA!
• Conclusions

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Conclusions

• Adaptive Hypermedia is a rapidly developing field
• development demands interdisciplinary efforts.
• Researchers, designers, educationalists, domain
  experts and software engineers must collaborate.
• A common language is needed.
• Instructional practises and theories to be
  reconsidered
• Standardisation efforts should be accelerated
• Evaluation schemes must be developed

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Closing

• Adaptive hypermedia is a powerful tool.
• Please use it wisely!
• Thank you.