adaptive hypermedia dr. alexandra cristea [email protected] acristea
TRANSCRIPT
• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
1. Adaptive Hypermedia of the Past, Present and Future
+ presentation m.
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/ presentation modeling interact with
each other (or else we say the application is adaptable, not adaptive)
is more than the Web!!
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
The need for personalization
Why AH?
• Problems with hypermedia applications:– information overload: no time or interest to process
all– excessive navigational freedom: “lost in
hyperspace” which links are relevant (for this user) ?
– comprehension: order (a.o.) may be relevant: what has the user seen before when reaching a certain node?
– presentation: what fits the user’s screen? how much network bandwidth and processing power is available?
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
Application areas AH• Areas
– Education– Commerce– Government– others
• Adaptation types– Adaptive Help– Adaptive Search– Expert systems – AI– others
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
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
Adaptive Presentation
Adaptive Navigation Support
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.…
ISIS Tutor with Link Annotation
The wrong example:
Example from Interbook
1. Concept role
2. Current concept state
3. Current section state4. Linked sections state
4
3
2
1
√
TV Scout: What’s on Tonight?
TV Scout: Forms and Graphical Interface
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
Adapt to what?
• User user model (UM)
• Goals goal model (GM)
• Domain domain model (DM)
• Environment presentation model (PM)
User modelling is always about guessing …
Classical User Model: Overlay UM• user’s knowledge = subset of expert’s
knowledge
• goal of tutoring: to enlarge this subset.
• This model is particularly appropriate when the (teaching) material can be represented as a prerequisite hierarchy.
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, age• Navigation history
User model population (initialization) ex.
Concept1
Concept2
Concept3
Knowledge: 0
Knowledge: 10
Knowledge: 20
Interest: 50
Age group: 10 years
Learning style: unknown
overlay free
Adapt to what?
• User user model (UM)
• Goals goal model (GM)
• Domain domain model (DM)
• Environment presentation model (PM)
Adapt to what?• Goal• (initial) purpose of the hypermedia• answer to question
– “Why should the user use the hypermedia system and what could the user actually 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 pedagogical / commercial goal.
Adapt to what?
• User user model (UM)
• Goals goal model (GM)
• Domain domain model (DM)
• Environment presentation model (PM)
Adapt to what?
Adapt to
Domain model properties
Adapt to what?
• User user model (UM)
• Goals goal model (GM)
• Domain domain model (DM)
• Environment presentation model (PM)
• Context / environment– aspects of the user’s environment, like
browsing device, window size, network bandwidth, processing power, quality of service, etc.
Adapt to what?
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt?• Obstacles AH• New solutions
Adaptation model
• How do the previous models interact (schematic model)
• The only dynamic part of the model
• Traditionally, a set of rules
Classic loop (Brusilovsky, ‘01) ++
φιπθθθ
/ Presentation Model
Adaptive vs. adaptable
adaptable adaptive
personalized
User-tuned System-tuned
Gerhard Fischer 1 HFA Lecture, OZCHI’2000
A Comparison between Adaptive and Adaptable Systems
Gerhard Fischer 1 HFA Lecture, OZCHI’2000
Index• Definitions• Why AH?• Application areas• What to adapt?• Adapt to what?• How to adapt - past?• Obstacles AH• New solutions
New, dynamic view of AH
text
link
Bits & piecesBit contains
text, MM or link
Generation: -only text
-only link
-text & link
text
text
link
link
Solutions in short
• Standardization
• Authoring
• Openness
New theoretical frameworks needed!
New implementations!
Concluding
Adaptive Hypermedia of Past, Present & Future– Definitions– Why AH?– Application areas– What to adapt?– Adapt to what?– How to adapt - past?– (some) New solutions
IAS and its Projects
• http://www.dcs.warwick.ac.uk/research/ias/
Reading:• read chapters 'The Adaptive Web':
– Adaptive Content Presentation, – Adaptive Navigation Support, – Open Corpus AEH,– Privacy-Enhanced Web Personalization, – Usability Engineering for Adaptive Web– See webpage for more
• From: http://www.springerlink.com/content/x646782t122p/
Any questions?