Context-aware computing has to deal with a huge amount of context data. Taking into account the quality of these data becomes a corner stone of an efficient context management solution. Information on the quality of context helps taking appropriate decisions and allows to identify uncertain context information saving processing time for deriving a pertinent description of the observed phenomenon. This paper presents a work in progress for integrating Quality of Context in COSMOS (COntext entitieS coMpositiOn and Sharing) [4,13], a component-based framework for managing context data in ubiquitous environments, and illustrates it throughout the example of the composition of context information to implement a network connectivity vs energy adaptation situation