For decades, researchers have presented different adaptive user
interfaces and discussed the pros and cons of adaptation on task
performance and satisfaction. Little research, however, has been
directed at isolating and understanding those aspects of adaptive
interfaces which make some of them successful and others not. We have
conducted several laboratory studies to systematically isolate some of
the design and contextual factors that affect the impact of adaptation
on users' performance and satisfaction. The results of these studies combined with the recent work of others, provide an initial characterization of the design space of adaptive graphical user interfaces.