As adaptivity in e-learning systems has become popular during the past years, new challenges and potentials have emerged in the field of adaptive systems. Adaptation, traditionally focused on the personalization of content, is now also required for learner communication and cooperation. With the increasing complexity of adaptation tasks, the need for automated processing of usage data, informat...

In recent years, emerging applications introduced new constraints for data mining methods. These constraints are typical of a new kind of data: the data streams. In a data stream processing, memory usage is restricted, new elements are generated continuously and have to be considered as fast as possible, no blocking operator can be performed and the data can be examined only once. At this time ...