oducing Personalization in Mediators The PAM-M is used to enhance a mediation system with personalization services. A mediation system gives a transparent access to a set of applications (sources). Each application communicates with the mediator through a particular wrapper. When a user sends a query to the mediation system, it is reformulated in order to be evalu- ated on the real applications. The PAMs deployment on a mediation system is shown in Figure 10.10. The role of the PAM-M is to adapt evaluation of the user query according to the user preferences and to the user context. In this case, applications do not have to be Service Delivery Platforms Profile warehouse PAM-M Mediation system Mediator meta data Context Wrapper Wrapper Wrapper Application Application Application Content Content Content Figure 10.10 Introducing personalization in mediators. aware of the personalization or of the PAM-M. The knowledge about users (pro- files) and contexts is stored at the PAM-M level and personalization is achieved at the mediator level. For example, when a user issues a query, the mediator can call the profile-context binding service in order to get the contextualized user profile. This profile and the initial query can then be sent to the query reformulation service in order to get a set of personalized query rewritings. The enriched rewritings can then be sent to the real applications in order to get relevant results according to the preferences stored in the user profile. 10.3.3.2 PAM-A: Introducing Personalization in Applications The PAM-A provides applications with personalized services and a persistent layer for profile and context management. The PAM-A is considered as being a part of the application (see Figure 10.11). Each application has its own PAM-A and thus, its own container of profile and context instances. However, in order to interoperate between applications, all PAM-A should share the same profile and context meta models. The PAM-A can be used in different manners according to the implication of t