A flexible layout model for a web-based adaptive hypermedia architecture

The paper presents an attempt to extend a general-purpose adaptive hypermedia (AH) architecture AHA! with flexible and rich interface by re-using some ideas explored in a more specific AH system InterBook. The most popular application (course) created with the old version of AHA! (the hypermedia course 2L670, later called 2L690, at the TU/e) used a single-window/single-frame concept representation which had advantages of its simplicity and clarity for the user. In this course concepts are always represented in a single frameless window. This mechanism is not sophisticated enough to serve as a general-purpose mechanism for concept representation. InterBook on the other hand has a much richer user interface characterized by the use of multiple windows and frames. This approach has more possibilities for representing the course domain, but has a problem of its rigid presentation structire. The author has no possibilities of adapting the user interface to the specific course which means that every course served by Interbook has the same look independent of the course characteristics. To address the lack of user interface possibilities in AHA! we developed the Layout model that employs the strong points of Interbook user interface. The dynamic structures of the Layout model are easily extendible and give author the power to adapt the user interface to the nature of the course.