Datafication has become an all-encompassing infiltrator in societal processes, among other the formation of publics and the actors that support such processes (i.e. journalism and information technologies). This article reviews four approaches to the study of public formation. These are (1) public and civic connections, (2) issue publics, (3) networked publics and (4) algorithmic publics. The review is a point of departure to conceptually discuss how to study the formation of public in a datafied era and to present a hybrid research agenda with four entry points that can open up for critical analysis of how datafication challenges the relationship between journalism, platforms, algorithms and audiences. Our argument is that a holistic, interdisciplinary and hybrid research approach is needed if the complexity of datafication and its transformative effects on the formation of publics is to be fully grasped.