University of Malta CSA3080: Lecture 12 © Chris Staff 1 of 22 CSA3080: Adaptive Hypertext Systems I Dr. Christopher Staff Department of Computer Science & AI University of Malta Lecture 12: Adaptation Techniques I

University of Malta CSA3080: Lecture 12 © Chris Staff 2 of 22 Aims and Objectives We will look at stages in the adaptation process and revisit the problems that AHS try to solve (this lecture) We will look at two example AHSs: Personal WebWatcher and MetaDoc, and some of the research that’s happening at UoM (next lecture)

University of Malta CSA3080: Lecture 12 © Chris Staff 3 of 22 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

University of Malta CSA3080: Lecture 12 © Chris Staff 4 of 22 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]

University of Malta CSA3080: Lecture 12 © Chris Staff 5 of 22 Problems Revisited Lost in HyperSpace Cognitive overload Complexity of the search space Search-browsing Static hypertext structure

University of Malta CSA3080: Lecture 12 © Chris Staff 6 of 22 Generic solutions Adaptive Presentation Adaptive Navigation

University of Malta CSA3080: Lecture 12 © Chris Staff 7 of 22 Lost in HyperSpace Mark-up nodes to include link to landmark which user knows about Show relationship between landmark node and current node Reduce cognitive load on user

University of Malta CSA3080: Lecture 12 © Chris Staff 8 of 22 Cognitive overload Move (some) linking functions into AHS system by, e.g., providing "See Also" links Automatic/dynamic linking Reduce number of outlinks by removing links to non-relevant nodes Link recommendation services

University of Malta CSA3080: Lecture 12 © Chris Staff 9 of 22 Complexity of the search space Removing links reduces the size of the search space Recommending links assists the user in deciding which links are likely to lead to relevant information Automatically modifying content enables readers to understand concepts at their level of understanding

University of Malta CSA3080: Lecture 12 © Chris Staff 10 of 22 Complexity of the search space Learn from user access paths to re-organise hyperspace Learn to associate user terminology with document content

University of Malta CSA3080: Lecture 12 © Chris Staff 11 of 22 Search-browsing Dynamic linking as a result of where user action is combined with any stated query terms Recommend links (paths) to relevant documents

University of Malta CSA3080: Lecture 12 © Chris Staff 12 of 22 Static hypertext structure Users can modify structure, and/or system can learn from users What change(s) to hypertext systems would be required? IR systems? Dynamic hypertext systems

University of Malta CSA3080: Lecture 12 © Chris Staff 13 of 22 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

University of Malta CSA3080: Lecture 12 © Chris Staff 14 of 22 Adaptation Technologies

University of Malta CSA3080: Lecture 12 © Chris Staff 15 of 22 Adaptive Presentation Anything to do with adapting how the presented material is displayed to users Examples –Adapting the UI (more to do with adaptive user interfaces than adaptive hypertext per se) –Modify data presentation so that it is presented in user's preferred choice (e.g., charts)

University of Malta CSA3080: Lecture 12 © Chris Staff 16 of 22 Adaptive Presentation More examples –Automatically expand/collapse glossary items according to user's level of expertise –Provide "trails" through hyperspace according to user's level of expertise –Can be fairly complex - if user does not know concept A, then unlikely to know concept B, so concept B should also be automatically expanded

University of Malta CSA3080: Lecture 12 © Chris Staff 17 of 22 Adaptive Presentation Adaptive presentation can be useful in any adaptive hypertext system, but mostly used in Intelligent Tutoring Systems

University of Malta CSA3080: Lecture 12 © Chris Staff 18 of 22 Adaptive Navigation Focused around implicit link types in Web- based systems (ideally, link types are explicit) Identify as many implicit link types as possible…

University of Malta CSA3080: Lecture 12 © Chris Staff 19 of 22 Direct Guidance Mainly through "Next" buttons! Can include link/path recommendation What are the pre-requisites?

University of Malta CSA3080: Lecture 12 © Chris Staff 20 of 22 Adaptive Sorting of Links Ordering links according to some ranking scheme On what basis? On which of the implicit link types can this be provided?

University of Malta CSA3080: Lecture 12 © Chris Staff 21 of 22 Adaptive hiding of links Hide links which would lead to non-relevant information What are the pre-requisites? In ITS systems? In generic AHSs? Identify implicit link types which support adaptive hiding

University of Malta CSA3080: Lecture 12 © Chris Staff 22 of 22 Adaptive annotation of links Mark-up anchor text/link description to explain the information at the destination of the link Description must be adaptive!