Delivering accessible content from Social Semantic Information Sources through Adaptive Hypermedia

Slide 1: Delivering accessible content from Social Semantic Information Sources through Adaptive Hypermedia Filip Maciej Czaja Filip Maciej Czaja SemInf, 23.05.2007 filip.czaja@deri.org www.deri.org  Copyright 2005 Digital Enterprise Research Institute. All rights reserved.

Slide 2: Presentation outline • Informal Knowledge • Social Semantic Information Sources (SSIS) • Accessibility and WAI Initiative • Adaptive Hypermedia (AH) • SSIS as dataset for AH • Future work 2

Slide 3: Motivation • Many information sources are not fully exploited. • Access to the web is still hard for disabled people. • Interesting adaptive hypermedia techniques work only on prepared datasets. • Semantic information is often omitted in content adaptation process. 3

Slide 4: Informal knowledge • Over 70% of our knowledge comes from informal sources • Everybody use them • Not well structured • No extensive documentation • Example: wikis, blogs, youtube, ... 4

Slide 5: Social Semantic Information Sources • Compilation of Semantic Web and social networking • Combine advantages of Web 2.0 and SW • Resources and people related to the resources are linked together • Semantic plugins available for most popular blogging frameworks, wikis, etc. • Common examples: semantic wikis, semantic blogs, semantic digital libraries (JeromeDL) 5

Slide 6: Model of SSIS • Common components between SSIS: – Content – Traditional content description (title, authors, ... ) – Semantic description (semantic metadata) – Semantic annotations • Aspect of user's collaboration • SIOC ontology for modelling SSIS 6

Slide 7: Main SIOC terms 7

Slide 8: Accessibility • Many various aspects of “accessibility” • What kind of accessibility do we mean? • Real life accessibility aspects: – Transportation – Housing – ... • Most common aspect of accessibility in Web: making the use of Web resources possible for disabled people

Slide 9: Web Accessibility Initiative (WAI) • Introduced by World Wide Consortium (W3C) • WAI aims at improving Web accessibility by developing the following products: – Web Content Accessibility Guidelines (WCAG) – Authoring Tool Accessibility Guidelines (ATAG) – User Agent Accessibility Guidelines (UAAG)

Slide 10: WAI components diagram

Slide 11: WAI vs. Rich Internet Applications • Rich Internet applications: – DHTML, AJAX, ... – Accessibility problems because of the (X)HTML limitations – Rich content not accessible for screen readers – Beauty & Usability & Innovation vs. Accessibility • WAI works on guidelines for Accessible Rich Internet Applications (ARIA) – providing information about user interface controls to assistive technologies – Roles, properties and states – Easy to apply 11

Slide 12: Adaptive hypermedia • Regular hypermedia structure base on large set of documents (text, media, etc.) linked together. • Adaptive hypermedia: – Concept of AH does not introduce any revolutionary technology – Techniques for adaptive content presentation and navigation based on model of the user – AH Techniques designed mostly for specially prepared hypermedia content (additional annotations, many variants of the same concept, etc.) 12

Slide 13: Adaptive hypermedia systems “By adaptive hypermedia systems we mean all hypertext and hyper- media systems which respect some features of the user in the user model and apply this model to adapt various visible aspects of the system to the user.” Peter Brusilovsky • 3 basic criteria for AH systems: – work on hypertext or hypermedia dataset – use a user model as a source of information about user's needs and preferences – should be able to adapt the data it works on (hypertext/hypermedia dataset) to user's needs according to the information extracted from user's mode 13

Slide 14: Adaptive Hypermedia: user model • Most common aspects used while modelling user in Adaptive Hypermedia systems: 14

Slide 15: Adaptable elements and methods • Presentation • Navigation – additional explanation – global guidance – prerequisite/comparative – local guidance explanations – global orientation support – explanation variants – local orientation support – sorting – managed personalized views 15

Slide 16: Adaptive Hypermedia Challenges • How to use existing information sources, which are not prepared for AH purposes? • How to convince authors to put extra effort? • Use of Adaptive Hypermedia in case of: – systems without limited, predefined set of tasks – fuzzy and constantly changing goals • User modelling related issues: – defining goals, knowledge, ... – gathering data – keeping data up to date 16

Slide 17: SSIS as dataset for AH • Possible use of existing information sources in AH systems without any manual data transformation • Which AH techniques can we use to improve browsing of SSIS (presentation, navigation, ...)? • Content is not prepared for AH purposes but contains semantic information • Reasoning over semantic metadata and annotations used for AH purposes: – comparative explanation – additional information – explanation variants – ... 17

Slide 18: IKAR – Informal Knowledge Adapter • Prototype for adaptation of presentation of SSIS content • Part of Didaskon eLearning Framework – Didaskon prepares content of SSIS basing on their semantic annotations and common structure – Content of SSIS delivered as Learning Object Metadata (LOM standard) – User modelling basing on FOAFRealm component • Adheres to WAI guidelines 18

Slide 19: IKAR: idea and techniques • Uses AH Strechtext technique for providing additional explanation • 3 classes of links:known, unknown and external • Default adaptation: – Known links collapsed – Unknown links expanded • 2 display modes: – regular (additional explanations injected into content) – sidenotes mode • Accessibility – WAI-ARIA guidelines applied: roles, properties and states – Automatic content transformation according to WCAG 1.0

Slide 20: IKAR: default adaptation example

Slide 21: IKAR: sidenotes mode example

Slide 22: Future work • Possible use of other AH techniques, also for navigation. • Improvement of Accessibility Adaptation engine. • Applying SSIS to real life eLearning scenarios as support or extension for formal knowledge 22