Users' data: Trails analysis

With the development of Web-based distance learning environments, acquiring and analysing trails has become a very important issue for the technology-enhanced learning (TEL) community. We consider a trail (or a track or a trace) as the digital or non-digital record that learners-or more generally, the different actors within a learning session in a TEL system-leave behind. This chapter addresses the life cycle of such trails from a computer science point of view. In particular, we elaborate on the engineering and usage of the different kinds of trails by highlighting the main scientific issues raised by the trails analysis process and by presenting research findings from the Kaleidoscope Network of Excellence in this field.