(De Bra, Aerts & Rousseau, 2002), for example, address the definition of higher-level concept relationship types and the automatic translation of instances of such types into lower-level adaptation rules for the AHA! adaptive eLearning system. Some of the relationship types discussed therein denote direct relationships between concepts and learning elements (e.g., concept A is a prerequisite for concept B, element X exemplifies concept C), while others bear a clear adaptation / knowledge inference flavour to them (e.g., element Y when read provides knowledge towards concept D, or, element Y when read indicates interest in concept E).