In an Ambient Intelligence system for humans, devices in the environment perform actions to improve the quality of the daily living of a person. Research in normative systems could be applied to regulate the operation of this kind of systems. Nevertheless, determining the right norms is not trivial. This contribution discusses the case of a Parkinson's Disease patient. In particular, the paper studies a TV watching scenario where the right moment to assist the patient is the subject of discussion. Results are obtained from the SociAAL project, whose aim is the integration of social sciences concerns into the development of this kind of systems and the reduction of their production cost.