Adaptive Hypermedia From Concepts to Authoring

1. Adaptive HypermediaFrom Concepts to Authoring Peter Brusilovsky School of Information Sciences University of Pittsburghpeterb@pitt.edu http://www.sis.pitt.edu/~peterb/

2. Adaptive systems Classic loop “user modeling - adaptation” in adaptive systems

3. Adaptive software systems • Intelligent Tutoring Systems • adaptive course sequencing • adaptive . . . • Adaptive Hypermedia Systems • adaptive presentation • adaptive navigation support • Adaptive IR systems • Adaptive . . .

4. Outline • Adaptive hypermedia • Where? • Why? • What? • How? • Who?... • Adaptive presentation • Adaptive navigation support

5. Adaptive hypermedia: Why? • Different people are different • Individuals are different at different times • "Lost in Hyperspace” • Large variety of users • Variable characteristics of the users • Large hyperspace

6. Where it can be useful? • Web-based Education • ITS, tutorials, Web courses • On-line information systems • classic IS, information kiosks, encyclopedias • E-commerce • Museums • virtual museums and handheld guides • Information retrieval systems • classic IR, filtering, recommendation, services

7. Where it can be useful? • Web-based education • ELM-ART, AHA!, KBS-Hyperbook, MANIC • On-line information systems • PEBA-II, AHA!, AVANTI, SWAN, ELFI, ADAPTS • E-commerce • Tellim, SETA, Adaptive Catalogs • Virtual and real museums • ILEX, HYPERAUDIO, HIPS, Power, Marble Museum • Information retrieval, filtering, recommendation • SmartGuide, Syskill & Webert, IfWeb, SiteIF, FAB, AIS

8. Adapting to what? • Knowledge: about the system and the subject • Goal: local and global • Interests • Background: profession, language, prospect, capabilities • Navigation history

9. Who provides adaptation? • User • "Administrator" • System itself • Adaptive vs. adaptable systems

10. What can be adapted? • Hypermedia = Pages + Links • Adaptive presentation • content adaptation • Adaptive navigation support • link adaptation

12. Adaptive presentation: goals • Provide the different content for users with different knowledge, goals, background • Provide additional material for some categories of users • comparisons • extra explanations • details • Remove or fade irrelevant piece of content • Sort fragments - most relevant first

13. Adaptive presentation techniques • Conditional text filtering • ITEM/IP, PT, AHA! • Adaptive stretchtext • MetaDoc, KN-AHS, PUSH, ADAPTS • Frame-based adaptation • Hypadapter, EPIAIM, ARIANNA, SETA • Full natural language generation • ILEX, PEBA-II, Ecran Total

14. Conditional text filtering • Similar to UNIX cpp • Universal technology • Altering fragments • Extra explanation • Extra details • Comparisons • Low level technology • Text programming If switch is known and user_motivation is high Fragment 1 Fragment 2 Fragment K

15. Example: Stretchtext (PUSH)

16. Example: Stretchtext (ADAPTS)

17. Adaptive presentation: evaluation • MetaDoc: On-line documentation system, adapting to user knowledge on the subject • Reading comprehension time decreased • Understanding increased for novices • No effect for navigation time, number of nodes visited, number of operations

18. Adaptive navigation support: goals • Guidance: Where I can go? • Local guidance (“next best”) • Global guidance (“ultimate goal”) • Orientation: Where am I? • Local orientation support (local area) • Global orientation support (whole hyperspace)

19. Adaptive navigation support • Direct guidance • Restricting access • Removing, disabling, hiding • Sorting • Annotation • Generation • Similarity-based, interest-based • Map adaptation techniques

20. Example: Adaptive annotation Annotations for topic states in Manuel Excell: not seen (white lens) ; partially seen (grey lens) ; and completed (black lens)

21. Adaptive annotation and removing

22. 1. Concept role 2. Current concept state Example: Adaptive annotation 4 3 2 v 1 3. Current section state 4. Linked sections state

23. Adaptive navigation support: major goals and relevant technologies

24. What can be adapted: links • Contextual links (“real hypertext”) • Local non-contextual links • Index pages • Table of contents • Links on local map • Links on global map

25. Link types and technologies

26. Adaptive navigation support: evaluation • Sorting • HYPERFLEX, 1993 • Annotation (colors) and hiding • ISIS-Tutor, 1995 • Annotation (icons) • InterBook, 1997 • Hiding • De Bra’s course, 1997

27. Evaluation of sorting • HYPERFLEX: IR System • adaptation to user search goal • adaptation to “personal cognitive map” • Number of visited nodes decreased (significant) • Correctness increased (not significant) • Goal adaptation is more effective • No significant difference for time/topic

28. Adaptive Hypermedia: our approach ITEM/IP, MSU (1986-1994) ISIS-Tutor, MSU (1992-1994) ITEM/PG, MSU (1991-1993) SQL-Tutor, MSU (1995-1998) ELM-ART, Trier (1994-1997) InterBook, CMU (1996-1998) ELM-ART II, Trier (1997-1998) ADAPTS, CMU (1998-1999) COCOA, CTE (1999-2000)

29. Annotation and hiding: ISIS-Tutor • An adaptive tutorial for CDS/ISIS/M users • Domain knowledge: concepts and constructs • Hyperspace of learning material: • Description of concepts and constructs • Examples and problems indexed with concepts (could be used in an exploratory environment) • Link annotation with colors and marks • Removing links to “not relevant” pages

30. Concepts, examples, and problems Example 1 Concepts Examples Concept 4 Example 2 Example M Concept 1 Concept N Problems Concept 2 Problem 1 Concept 5 Problem 2 Problem K Concept 3

31. Indexing and navigation Example 1 Concepts Examples Concept 4 Example 2 Example M Concept 1 Concept N Problems Concept 2 Problem 1 Concept 5 Problem 2 Problem K Concept 3

32. Student modeling and adaptation • States for concepts: • not ready (may be hidden) • ready (red) • known (green) • learned (green and ‘+’) • State for problems/examples: • not ready (may be hidden) • ready (red) • solved (green and ‘+’)

33. Sample index page (annotation)

34. Sample index page (hiding)

35. ISIS-Tutor: Evaluation • 26 first year CS students of MSU • 3 groups: • control (no adaptation) • adaptive annotation • adaptive annotation + hiding • Goal: 10 concepts (of 64), 10 problems, all examples

36. Experiment design

37. Results: performance Adaptive annotation makes navigation more efficient

38. The value of adaptivity: steps

39. The value of adaptivity: repetitions

40. Results: navigation No effect on navigation patterns due to variety of navigation styles

41. Results: recall No effect on recall

42. To hide or not to hide? Additional value of hiding is unclear. Users prefer “freedom”

43. Evaluation of hiding • Adaptive course on Hypertext (De Bra) • Hiding “not ready” links • Hiding obsolete links • Small-scale evaluation • No significant differences • Students are not comfortable with disappearing links

44. InterBook: concept-indexed ET • “Knowledge behind pages” • Structured electronic textbook (a tree of “sections”) • Sections indexed by domain concepts • Outcome concepts • Background concepts • Concepts are externalized as glossary entries • Shows educational status of concepts and pages

45. Sections and concepts Textbook Chapter 1 Chapter 2 Section 1.2 Section 1.1 Section 1.2.1 Section 1,2,2

46. Sections and concepts Textbook Domain model Concept 4 Chapter 1 Concept 1 Concept n Chapter 2 Concept 2 Section 1.2 Section 1.1 Concept m Concept 3 Section 1.2.1 Section 1,2,2

47. Indexing and navigation Textbook Domain model Concept 4 Chapter 1 Concept 1 Concept n Chapter 2 Concept 2 Section 1.2 Section 1.1 Concept m Concept 3 Section 1.2.1 Section 1.2.2

49. Glossary view

50. Navigation in InterBook • Regular navigation • Linear (Continue/Back) • Tree navigation (Ancestors/Brothers) • Table of contents • Concept-based navigation • Glossary (concept -> section) • Concept bar (section -> concept) • Hypertext links (section -> concept)