GALE: a highly extensible adaptive hypermedia engine

This paper presents GALE, the GRAPPLE Adaptive Learning Environment, which (contrary to what the word suggests) is a truly generic and general purpose adaptive hypermedia engine. Five years have passed since "The Design of AHA!" was published at ACM Hypertext (2006). GALE takes the notion of general-purpose a whole lot further. We solve shortcomings of existing adaptive systems in terms of genericity, extensibility and usability and show how GALE improves on the state of the art in all these aspects. We illustrate different authoring styles for GALE, including the use of template pages, and show how adaptation can be defined in a completely decentralized way by using the open corpus adaptation facility of GALE. GALE has been used in a number of adaptive hypermedia workshops and assignments to test whether authors can actually make use of the extensive functionality that GALE offers. Adaptation has been added to wiki sites, existing material e.g. from w3schools, and of course also to locally authored hypertext. Soon GALE will be used in cross-course adaptation at the TU/e in a pilot project to improve the success rate of university students.