Virtual butler: what can we learn from adaptive user interfaces?

In this paper, we discuss approaches and results from the field of User-Adaptive Interfaces that we believe can help advance the research on virtual butlers in general, and for the elderly in particular. We list principles underlying the design of effective mixed-initiative interactions that call for formal approaches to dealing both with the uncertainty on modeling relevant cognitive states of the user (e.g., goals, beliefs, preferences), as well as with the tradeoff between costs and benefits of the agent's actions under uncertainty. We also discuss the need for virtual butlers to understand the affective states of their users, and to what extent they need to be transparent by providing means for their users to understand the rationale underlying their adaptive interventions.