In the analysis of communicational practices — whether in the form ofaudience, audience, consumers, users, recipients, participants, spectators —there is an imprecision of terms and occurrences that leaves room forterminological and theoretical indecision. Hence the desire to clarify thecontours of the notion of public, while relying on empirical material, and toexamine its multiple transformations. Thanks to a collective interdisciplinary program, researchers in informationand communication sciences and in language sciences from the Center forResearch on Mediations of the University of Lorraine have studied theconditions of production and diffusion of information and knowledge, theattitudes and behaviors of the public, the mechanisms of intercomprehensionor of communicational blockages and the weight of technological factors in mediations. These issues are addressed using methods that combine sociological surveys, targeted ethnographic studies,experiments, and corpus analyses. They are applied to a variety of fi elds,extending work that has already been done, but also shaking up certainresults. This book gathers a selection of signifi cant studies around four sections:the concept of public space; the relationship to the digital; innovations inthe fi eld of health; the relationship to writing in the cultural sector.