The present paper describes recent work with a type of automation that is adaptive in nature. In systems that use adaptive automation, the level of automation, the number of automated systems, or the format of the interface can be modified in real time. Often, these systems behave like computer teammates. Attention is focused on two types of adaptive automation: 1) behavior-based and 2) a brainbased systems. Recent research on these systems is described and the findings are discussed with respect to performance and user acceptance.