Context awareness is a necessary feature for mobile collocated collaborative learning. In this paper we describe how requirements for contextaware cooperative learning activities are derived from the jigsaw technique augmented with the use of mobile devices, applications to support the activities of groups, and tools to provide context-awareness to detect group formation. The emergence of groups is detected based on the location of the students within the classroom, but this information has to be careful filtered to evaluate the degree of uncertainty and protect from erroneous estimations. A three-phase strategy to manage uncertainty by identifying possible sources of uncertainty, representing uncertain information, and determining how to proceed under the presence of uncertainty is used for this propose. These requirements are validated and confirmed in experiments with students working together in the classroom, measuring neutral or positive effects on learning and the usefulness of introducing mobile devices, group support applications, and context awareness. The ratio of unwanted interruptions to users made by the system is used to evaluate the utility of the system. Results show that by managing uncertainty, location estimation becomes more reliable, thus increasing the usefulness of the learning application.