This module (18hours) aims to set down the basis of ergonomy and cognitive psychology required to elaborate systems (of information, production, action...) where people have a central role either as users or as essential links in the cooperation chain. Such elaboration needs basic knowledge of 'the human processing of information'. A number of models are also present in the course( coming either directly from a psychological approach or relying on the analysis of a user-system dialogue etc.) which may be applied to the definition and specification of services. The course concludes with an overview of practical methodologies inspired by these models but allowing us to tackle ergonomic aspects of system design and services in a concrete manner.