In this paper, an argumentation-based deliberative approach for fusing contextual information obtained from heterogeneous sources using a multi-agent system is introduced. The system is characterized by three different agents: an Environment Agent, an Activity Agent and a Coach Agent. These agents consider data from heterogenous sources of data. As a method for aggregating data and supporting decision-making, so-called agreement rules are instrumental in the argumentation-based deliberative method. The aggregation rules will be associated to specific beliefs related to the services of each agent.