ee aspects are described in this dimension: details about the used device (e.g., type, autonomy, memory storage, and computing power), the software that is used (e.g., operating system, mail client, etc.), and characteristics of the connection (e.g., Type: WiFi, 3G; Rate; Services: FTP, MMS). The environment dimension concerns elementary sensors that may inform appli- cations about external characteristic of users' environments. These sensors may be used to capture temperature, luminosity, and SO on. Smart home applications [47], Context Context dimension Temporal UserStat Environment Spatial Interaction Figure 10.2 Context model. Service Delivery Platforms for example, aim to automate the management of these sensors in order to satisfy users' preferences. The user-state dimension provides information about the user availability and cognitive emotions. Some applications such as automated hotline agents deal directly with users; therefore, they need to infer the user emotions in order to adapt the dialog. Further, interactions have to be adapted to the user availability, for example, when a user is in a meeting, the personalized application will contact him by email instead of SMS. Similarly to the profile model, the context model can be customized by the same set of operations (hiding model elements, defining new elements, and renam- ing elements) to fulfill specific application needs. 10.2.3 Profile and Context Management Platform Profile and context models constitute a foundation to understand or build various personalized applications. They may also be considered as a mean to interoperate between heterogeneous personalized applications as they make their specific pro- files and contexts simple customizations or instances of our generic models. Customization and instantiation are then model management operations that allow users, application designers, or any learning-based agents to adapt these models to application needs and create concrete profiles and contexts. The set of customiza- tion operations consists