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Last update: 2005-05-20

AHA! progress report December 4, 2001

[Adaptive Hypermedia for All! — concluded in 2003]


The NLnet AHA project has started on July 1, 2001, when one of the two appointed junior researchers, Natash Stash, commenced work at the TU/e. Problems with the second researcher are still not resolved. Luckily, four students have more than compensated for this. The AHA team now consists of the following people:

  • Natasha Stash is employed full-time by the AHA project for the duration of the project (one or two years depending on funding).
  • Jurgen van Westreenen has been a full-time intern at TU/e from September 1, 2001 to November 30, 2001.
  • David Smits is a part-time intern at TU/e from September 1, 2001 to February 28, 2002.
  • Davy Floes is a thesis student at UIA from October 1, 2001 to June 30, 2002.
  • Koen Verheyen is a thesis student at UIA from October 1, 2001 to June 30, 2002.
In addition, supervision is provided by prof. dr. Paul De Bra, and when needed also by dr. Ad Aerts, dr. Lora Aroyo, dr. Licia Calvi, dr. ir. Alexandra Cristea and dr. ir. Geert-Jan Houben.

Achievements up to this date

The status of the AHA project as of November 30, 2001 is described below. It lists the items that have been realized that were not in the current production version of AHA.

  • AHA has been ported to the Apache/Tomcat server. (The production version only works with Sun's JSWDK, a minimal server built on top of the Servlet runner.)
  • The syntax of pages has been integrated with that of headers and footers so that there is now a single DTD.
  • It is now possible to "register" as an anonymous user, and to carry anonymous sessions over between browser sessions (on the same machine and under the same username).
  • Pages from external servers can now be served through AHA, making it an "Open Hypermedia" system. External documents may be in one of three formats:
    • AHA XML format (just like local AHA pages);
    • AHA HTML format (HTML mixed with AHA XML tags);
    • HTML format
    There are some limitations with pages containing Images, Java Applets, or JavaScript code, but these are limitations with all possible filters that are HTTP servers and retrieve documents from other HTTP servers.
  • A Java Applet based editor for "requirement rules" has been created.
  • Database support has been added for the mySQL database system. Through a simple switch the main files for adaptation (requirement list, generate list) and all user models can be stored either as XML files or as database tables.
  • The concept structure has been changed so that user-model concepts can now have multiple attributes. This change has been incorporated in the requirements editor and the database support, but not yet in the main engine. (As a result it cannot yet be fully used.)

Future Milestones

The parts currently being worked on in the AHA project, and the corresponding milestones, are as follows:

  • The Apache support, unified page DTD, anonymous login, external document loading and mySQL database support will be integrated into a single code base. This task will be performed by Natasha Stash and completed by January 15, 2002.
  • The core engine will be extended with support for concepts with multiple attributes. This task will be performed by David Smits and completed by February 28, 2002. (This is also the end-date of his internship.)
  • Based on the work described above, a new release of AHA will be published on the AHA website on March 1, 2002.
  • A combined editor for generate and requirement rules will be built, extending the requirement editor (completed on November 30, 2001). This task will be performed by Koen Verheyen. A first partial prototype of this editor (perhaps not yet "connected" to the AHA engine) will be completed by February 28, 2002, and the "final" editor will be completed by May 31, 2002.
  • The current modules for multiple-choice tests, user-model updates and preferences, will be integrated and extended to form a general-purpose forms interface. This task will be performed by Davy Floes. The design of this interface (definition of the types of forms, XLML representation, and authoring interface) will be completed by January 15, 2002. A first partial prototype will be completed by February 28, 2002, and the "final" editor and engine support will be completed by May 31, 2002.
  • The rules that are possible with the new rule editors and engine can exhibit undesirable behavior (problems with termination and confluence). Natasha Stash will investigate the problem of predicting and detecting these situations. This will result in a verification module to be incorporated into the rule editor and completed by May 31, 2002.
  • An editor for AHA pages will be built. The editor will enable authors to create skeleton pages consisting of conditional fragments. The content of the fragments can be arbitrary data or HTML. For HTML fragments an editor will be included. This task will be performed by Olga Proskura. A first prototype, including at least the editor for skeleton pages (without an HTML editor) will be completed by May 31, 2002.
  • The period of June 1, 2002 to June 30, 2002 will be used to integrate the tools and the documentation. A new AHA release will be published on July 1, 2002.
Developments of the AHA project can be followed on the AHA website, at the address

The AHA project, and the prototype system will be submitted for demonstration to (at least) the following international conferences:

  • WWW2002, The Eleventh International World Wide Web Conference, Honolulu, USA, May 7-11, 2002.
  • AH2002, The Second International Conference on Adaptive Hypermedia and Adaptive Web-Based Systems, Malaga, Spain, May 29-31, 2002.
  • HT2002, ACM Conference on Hypertext and Hypermedia, College Park, Maryland, USA, June 11-15, 2002.