1. Introduction
Brusilovsky [1] envisages Web-based adaptive courses and systems as being able to achieve some important features including the ability to substitute teachers and other students support, and the ability to adapt (and so be used in) to different environments by different users (learners). These systems may use a wide variety of techniques and methods. Among them, curriculum sequencing technology “is to provide the students with the most suitable individually planned sequence of knowledge units to learn and sequence the learning tasks … to work with”. These methods derive from adaptive hypermedia field [2] and rely on complex conceptual models, usually driven by sequencing rules [3], [4]. E-learning traditional approaches and paradigms, that promote reusability and interoperability, are generally ignored, thus resulting in (adaptive) proprietary systems (such as AHA! [5]) and non-portable courseware.