More and more interactions take place between humans and mobile or connected IT-systems in daily life. This offers a great opportunity, especially to user modelling, to reach better adaptation with ongoing evaluation of user behaviour. This work develops a complete framework to realize the newly defined concept of ubiquitous user modelling. The developed tools cover methods for the uniform exchange and the semantic integration of partial user models. They also account for the extended needs for privacy and the right of every human for introspection and control of their collected data. The SITUATIONAL STATEMENTS and the exchange language USERML have been developed on the syntactical level, while the general user model ontology GUMO and the UBISWORLD ontology have been developed on the semantic level. A multilevel conflict resolution method, which handles the problem of contradictory statements, has been implemented together with a web-based user model service, such that the road capability and the scalability can be proven with this approach.