Every learning situation is designed according to specific instructional objectives. Instructional designers evaluate the correlation between the objectives and the real progress of the learning session by practicing an observation activity. In order to be efficient, the observation must be organized. Our goal in this work aims to provide tools and methods to support the observation activity. That is why we propose the concept of Observing Strategy. In this paper, we present a concrete observation strategy formalization to illustrate our proposition. We also present two processes: the first one focuses on the specification of executable observation strategies by considering the elements of instructional scenario, the links between pedagogical indicators and observation means and the machinereadable format of all this information. The second one focuses on specifying an observation strategy by the user through the manipulation of dedicated tools.