1. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 1 of 15 cstaff@cs.um.edu.mt CSA4080: Adaptive Hypertext Systems II Dr. Christopher Staff Department of Computer Science & AI University of Malta Topic 7: Adaptation Techniques

2. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 2 of 15 cstaff@cs.um.edu.mt Aims and Objectives Review of stages in the adaptation process and adaptation techniques from CSA3080 Adaptive navigation in Letizia, WebWatcher, and HyperContext

3. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 3 of 15 cstaff@cs.um.edu.mt Stages in the Adaptation Process Collect data about the user Process data to build/update user model Apply user model to provide the adaptation –Last stage always fully automated in adaptive hypertext systems –1st and 2nd stages may require user intervention. Ideally, fully automated

4. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 4 of 15 cstaff@cs.um.edu.mt Stages in the adaptation process If user and system need to co-operate to achieve adaptivity, then it is called collaborative user modelling From [Brusilovsky96]

5. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 5 of 15 cstaff@cs.um.edu.mt Problems Revisited Lost in HyperSpace Cognitive overload Complexity of the search space Search-browsing Static hypertext structure

6. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 6 of 15 cstaff@cs.um.edu.mt Generic solutions Adaptive Presentation Adaptive Navigation

7. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 7 of 15 cstaff@cs.um.edu.mt What can be adapted? A hypertext is a collection of nodes that are connected by links So what can be adapted? –The node content and user interface - adaptive presentation –The node organisation and hyperspace representations (e.g., index, map, overview) - adaptive navigation

8. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 8 of 15 cstaff@cs.um.edu.mt Adaptation Technologies

9. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 9 of 15 cstaff@cs.um.edu.mt Adaptive Navigation Adaptive Navigation-local reconnaissance is highly related to link annotation E.g., Letizia, WebWatcher, Personal WebWatcher, HyperContext Already talked about Personal WebWatcher in Topic 4 (User Modelling) and CSA3080

10. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 10 of 15 cstaff@cs.um.edu.mt Adaptive Navigation Differences in ITS and generic approaches to adaptive navigation –ITS aim is to transfer knowledge efficiently by guiding through a learning space Learned, ready to be learned, not ready to be learned –Generic aim is to guide user through document space to relevant information (that is ideally also at the level of simplicity required by user!) Relevant, not relevant (what about “related to interest X?”)

11. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 11 of 15 cstaff@cs.um.edu.mt Adaptive Navigation Letizia –Predicts a user’s interest as the user browses and suggests links to relevant document in the vicinity of the user’s current location –User tends to traverse Web graph “downwards”, but relevant information may lie sideways –Observes user behaviour to determine user interests (eg, “skipping” links, bookmarking...) –Makes recommendations based on “persistence of interest” lieberman95letizia.pdf

12. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 12 of 15 cstaff@cs.um.edu.mt Adaptive Navigation WebWatcher –Guides users through a web site based on interaction with past users –Users express a query and are guided to relevant documents –Associates what users are interested in with documents that they mark as relevant –Marks up links with terms used by users, and terms that occur in “downstream” documents webwatcher.ijcai97.pdf

13. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 13 of 15 cstaff@cs.um.edu.mt Adaptive Navigation HyperContext –Uses Information Retrieval-in-Context to guide users to information in hyperspace (up to 7 link traversals away) –Once user has navigated to a location which probably contains information, can submit query to search “context sphere” –With Adaptive Information Discovery, system generates query on behalf of user HCTCh5.pdf

14. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 14 of 15 cstaff@cs.um.edu.mt Adaptive Presentation Already described MetaDoc’s Stretchtext functionality in CSA3080 Approaches are generally intended to make the content more understandable to the user –automatically including glossary explanations of terms unknown to the user –removing extraneous information, or information known to the user –showing information in format preferred by user...

15. University of Malta CSA4080: Topic 7 © 2004- Chris Staff 15 of 15 cstaff@cs.um.edu.mt Summary Reminded ourselves of the problems that AHSs try to fix The adaptation process Adaptation technologies Examples of systems that incorporate adaptive navigation techniques