Dialog systems that adapt to different user needs and preferences appropriately have been shown to achieve higher levels of user satisfaction [1]. However, it is also important that dialog systems be able to adapt to the user’s computing environment, because people can access computer systems using different devices. Existing research has focused on either user-centered adaptations or device-centered adaptations. To my knowledge, no work has been done on integrating and coordinating both types of adaptation interdependently. In this thesis, I aim to investigate how multimodal dialog systems can adapt their content and style of interaction to individual users and their current device. The primary contribution of this thesis will be a framework that extends and combines both types of multimodal content adaptations that should occur in dialog systems.