adaptive hypermedia

Adaptive Hypermedia

Dr. Alexandra Cristeaa.i.cristea@warwick.ac.uk

http://www.dcs.warwick.ac.uk/~acristea/

• 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 role2. 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

linkBits & pieces Bit contains

text, MM or link

Generation: -only text

-only link

-text & link

text

textlink

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?