1 A Dynamic Model Balancing User Control and Workload in Automatic and Adaptive Systems

Current interactive systems are criticized for having complex interfaces that overload users with information. Two possible solutions to manage overload are automatic interfaces that augment user capa-bilities, and user-controlled systems that provide support. These two types of interfaces introduce a trade-off: On the one hand, automatic interfaces alleviate workload but create performance problems associated with the absence of control. On the other hand, user-controlled interfaces afford users more control, which may come with additional workload. Based on the analysis of adaptive user interfaces and automation, a model is proposed where automatic and user interface adaptation are in a multidimensional and contin-uum-based space, allowing for modelling dynamic changes to the roles the human and machine play at various stages of interaction