We present an approach for the follow-up of human activity in the complementary settings of health monitoring and collaborative work. Rather than aimed at providing an accurate and complete description of this activity, our system is aimed at framing the perception or interpretation processes according to various universes of discourse and evolving requirements: the one of the application domain, the one of the human acting or observing this activity, the one of the technical system at hand. We further promote a unified designing approach grounded in normative multi-agent systems theory. We discuss the approach potential with respect to (i) human activity monitoring, (ii) support to tangible collaborative activity.