his paper argues that, despite the changes in philosophies and techniques that have occurred since ITS research began, there are continuous threads running through this research which define its essential and distinctive nature. In particular, ITSs are computer-based learning systems which attempt to adapt to the needs of learners and are therefore the only such systems which attempt to 'care' about learners in that sense. Also, ITS research is the only part of the general IT and education field which has as its scientific goal to make computationally precise and explicit forms of educational, psychological and social knowledge which are often left implicit. (http://aied.inf.ed.ac.uk/members99/archive/vol_10/self_paper/full.html)