Specification Framework for Engineering Adaptive Web Applications

1
Specification Framework for Engineering Adaptive
Web Applications

• Flavius Frasincar
• Geert-Jan Houben
• Richard Vdovjak

Databases Hypermedia Group Department of
Computer Science
2
Overview

• Introduction, Motivation and Goals
• Hera Design Methodology
• Conceptual Design
• Application Design
• Adaptation Design
• Prototype/Rendering
• Summary and Future Work

3
Introduction
1436 Printing Press (Johan Guttenberg) -
facilitated storing and exchange of
information/knowledge on a larger scale 1989
WWW (Tim Berners-Lee) - information/knowledge
exchange boost - everything is on the Web !?
- huge success vs. huge mess
4
Motivation

• There are several methodologies for manual
  hypermedia presentation design but not so for
  automated design.
• The need for presentation automation is justified
  by the fact that most WIS are data driven
• There is an increasing need for presentation
  adaptation for different users/user platforms.

5
Goals

• Develop a framework that supports automated
  hypermedia presentation design for WIS
• Integrates heterogeneous data sources.
• Facilitates presentation (server/client-side)
  adaptation
• Network (T1, 128K, 56K etc.)
• Display (PC, Palm, WAP Phone etc.)
• User (preferences, interaction history etc.)
• Enables semi-structured data queries.

6
Hera Design Methodology

• Originates from RMM (Relationship Management
  Methodology).
• Suggests a sequence of design steps to be taken
  when designing a web application.
• Supports
• integration of heterogeneous information
• automated presentation design
• user/platform adaptation

7
Design Methodology Steps, Models, and Processing
Engines
8
Conceptual Model (CM)

• Provides a uniform semantic view over different
  data sources that are integrated within a given
  Web application.
• Consists of hierarchies of concepts relevant
  within the given domain, their properties, and
  relations.
• Encoded in RDF(S).

9
Conceptual Model Example
10
CM Example RDF(S) Syntax
11
Application Model (AM)

• Describes hypermedia aspects of the presentation.
• Captures the navigational view over the CM
• Consists of (nested) slices and slice
  relationships
• Slices - meaningful presentation units
• Associated to concepts from the CM
• Contain properties and possibly other slices
  (nesting)
• Slice relationships
• Aggregation relationships index, tour, indexed
  guided tour
• Reference relationships link with an anchor
  specified.
• Encoded in RDF(S).

12
Application Model Example

13
AM Example RDF(S) Syntax
14
Adaptation/User Model

• Captures two kinds of adaptation
• Adaptability takes into account the situation in
  which the user will use the presentation (e.g.
  the browsing platform).
• Adaptivity means that the presentation changes
  itself according to the state of the users
  mind while being browsed.
• Consists of
• Device/User Profile captures static visual and
  platform preferences encoded in CC/PP.
• User Session represents the dynamic users state,
  e.g. did the user visit (learn) this slice
  (concept).
• Application and Update Rules describe the
  behavior of the presentation (e.g. conditional
  slices in AM) and keep the User Session
  up-to-date (AHAM rules).

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Adaptation Model Example
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Adaptation Model Syntax

• Adaptability Condition
• Adaptivity Condition

ltrdfsClass rdfIDSlice.painting.picture
sliceconditionprfImageCapableYe
sgt ltrdfsubClassOf rdfresourceSlice/gt lt/
rdfsClassgt
ltrdfsClass rdfIDSlice.painter.main
sliceconditionusBiography falsegt
ltrdfsubClassOf rdfresourceSlice/gt lt/rdfs
Classgt
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Profile Example

• Device/User Profile (CC/PP encoding)
• Screen size 100x80, preferred language English

ltccppcomponentgt ltupUserPreferencesgt
ltupLanguagegtEnglishlt/upLanguagegt
lt/upUserPreferencesgt
lt/ccppcomponentgt lt/rdfDescriptiongt
ltrdfDescription rdfaboutProfilegt
ltccppcomponentgt ltprfHardwarePlatformgt
ltprfImageCapablegtNolt/prfImageCapablegt
ltprfScreenSizegt100x80lt/prfScreenSize
gt lt/prfHardwarePlatformgt
lt/ccppcomponentgt
18
Update Rule (AHA) Example

• Update the Biography record in the User
  Session table to true after the user visited
  Slice.painter.main.

ltusSlice.painter.maingt ltahaupdatelistgt
ltahaSetOfConceptsgt
ltahaitemgtltusBiography ahaupdatetrue/gtlt/ahai
temgt lt/ahaSetOfConceptsgt
lt/ahaupdatelistgt lt/usSlice.painter.mai
ngt
US Value
us.Biography(Rembrandt) false
US Value
us.Biography(Rembrandt) true
19
Presentation Model

• Based on the concept of region which contains
  attributes and possibly other regions.
• Each region has a rectangular area associated.
• Slices are translated to regions, one slice can
  be mapped to several regions.
• Slice relationships are materialized with
• Navigational relationships
• Spatial relationships
• Temporal relationships

20
Region Relationships

• All region relationships can be guarded by a
  condition and/or an event.
• Navigational relationships represent the
  classical hyperlinks. Possible events are
  mouse-click, mouse-over etc.
• Temporal relationships have associated a timeout
  event (e.g. time based on a media play duration).
• Spatial relationships specify a relative
  position (qualitative or quantitative) between
  two regions.

21
Presentation Model Example
22
Synchronization

• Petri-net like notation for expressing
  synchronization (typical for multimedia data).
• Temporal
• Multidimensional

23
Prototype

• XSLT code generation
• Two code generators
• HTML for PC Web browsers
• WML code for WAP phone browsers

WML
XSL
HTML
XSL
ltxsltemplate matchslice-instancegt
ltTABLEgt ltxslapply-templates
select/gt lt/TABLEgt lt/xsltemplategt
ltxsltemplate matchslice-instancegt ltCARD
id_at_idgt ltxslapply-templates
select/gt lt/CARDgt lt/xsltemplategt
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Rendering
25
Summary

• Hera methodology originated from RMM suggests a
  sequence of design steps.
• Our framework supports
• integration of heterogeneous information (CM
  populated from several heterogeneous data
  sources)
• automated presentation design AM serves as a
  presentation blue print from which a concrete
  presentation is derived (wrt. a query)
• user/platform adaptation (adaptability and
  adaptivity)

26
Future Work

• Adaptation in all design steps including the
  Conceptual Model and Integration Model.
• Experiment with higher ontology languages (e.g.
  Oil) as the basis for the CM.
• Further development of tools for presentation
  rendering.
• Authoring tools that would help the designer to
  build specification models in all design steps.