1212 / department of computer science October 16, 2002AHA! Version 2.01 AHA! Version 2.0 More Adaptation Flexibility for Authors Paul De Bra, Ad Aerts, David Smits, Natalia Stash Eindhoven University of Technology

1212 / department of computer science October 16, 2002AHA! Version 2.02 Overview How do (Web-based) adaptive hypermedia systems work? Special-purpose vs. general purpose AHS. AHA! Version 2.0 Authoring the AHA! concept structure and adaptation rules New developments

1212 / department of computer science October 16, 2002AHA! Version 2.03 How do (Web-based) AHS work? 1.The user accesses a page (clicks on a link). 2.The system loads a domain model with the conceptual structure of the application. 3.The system loads an overlay user model. 4.The system loads an adaptation model with rules for updating the user model and for generating the adaptation. 5.The system executes these rules, resulting in an updated user model and a presented page.

1212 / department of computer science October 16, 2002AHA! Version 2.04 Differences between AHS: domain model (DM) consists of concepts, pages, fragments, and relationships. –systems may or may not consider high- level concepts, or low-level fragments; –systems may or may not consider relationships other than hyperlinks; –systems may have a fixed set of relationship types or allow the creation of new types.

1212 / department of computer science October 16, 2002AHA! Version 2.05 Differences between AHS: user model (UM) contains an overlay of the domain model. –systems may maintain many attributes about each domain model entity or not; attributes can be Boolean, integer, enumerated, etc. –level of granularity of UM may differ from DM, e.g. not having fragments in UM. –systems may allow the creation of attributes or not.

1212 / department of computer science October 16, 2002AHA! Version 2.06 Differences between AHS: adaptation model (AM) contains rules for updating the user model and for generating adaptation. –systems may have built-in rules, possibly associated with concept relationship types; –systems may allow authors to create specific adaptation rules; –systems may allow the association of new generic rules with concept relationship types.

1212 / department of computer science October 16, 2002AHA! Version 2.07 Special-purpose AHS Fixed structure of DM: limited set of concept relationship types. Fixed structure of UM: limited set of attributes per concept (or page), and of fixed type. Fixed AM: generic adaptation rules associated with the relationship types. Fixed presentation style, e.g. with “frames” for navigation and orientation aids.

1212 / department of computer science October 16, 2002AHA! Version 2.08 General-purpose AHS Author can define her own concept relationship types in DM; Author can choose which attributes to associate with which concepts in UM; Author can define specific and generic adaptation rules; Author can create any desired presentation style.

1212 / department of computer science October 16, 2002AHA! Version 2.09 DM: concepts, pages and fragments; authoring done in xhtml (plus AHA! tags); UM: author can define arbitrarily many attributes (Boolean, integer or string) for every concept or page AM: author defines condition-action (CA) rules for updating UM. author defines conditions for the “suitability” of links to pages and for the inclusion of fragments.

1212 / department of computer science October 16, 2002AHA! Version Example (page) concept de_koninck dk.xhtml beer.interest > concept de_koninck is a page concept links to this page are suitable if beer.interest > 50 de_koninck has a system-defined attribute “access”, not stored in UM, not changeable by the user.

1212 / department of computer science October 16, 2002AHA! Version Example adaptation rule beer.interest beer interest beer.interest+10 each attribute has a set of CA-rules; condition: beer.interest < 100 action: beer.interest incremented by 10 there can also be a set of falseActions

1212 / department of computer science October 16, 2002AHA! Version Concept Authoring Interface

1212 / department of computer science October 16, 2002AHA! Version Concept Authoring Interface (cont.)

1212 / department of computer science October 16, 2002AHA! Version Page authoring Pages are XHTML extended with AHA! tags for conditional inclusion of fragments. conditional fragment included here. Pages can have a header and footer, in a special XML format, and included using the tag.

1212 / department of computer science October 16, 2002AHA! Version New developments AHA! has no concept relationship types and no generic adaptation rules: come to the talk today, session 4-5pm! Pages are not standard xhtml. We are moving the conditions for fragments to the adaptation model. The conditions for fragments and pages are evaluated on the fly. We are adding an extension to allow “fixing” the conditions to generate stable presentations.

1212 / department of computer science October 16, 2002AHA! Version AHA! Development Status AHA! prerelease 1.98 is available for download from –Open Source, entirely in Java; –Uses Tomcat Java-Based Webserver; –Includes easy installation instructions, for Windows and Unix (Linux). Please try AHA! and give us feedback.