  We present a survey of recent research studies of the implementation of
adaptive user models in human-computer interaction. A classification of
research directions on adaptive user interfaces is first proposed; it takes
account of the user characteristics that are modelled, the distribution of
initiative and control of the system evolution between user and system, and the
role of dynamic adaptation. Then, a few representative research studies are
briefly presented to illustrate this classification. In the conclusion, some
major issues regarding the utility and usability of adaptive user interfaces
and the design of an appropriate methodology for assessing the ergonomic
quality of this new form of interaction are mentioned.
