Claudia Mellado is a professor of journalism in the School of Journalism at the Pontificia Universidad Católica de Valparaíso (PUCV), Chile, and a Fellow of the International Communication Association. Her research focuses on the study of journalism cultures, journalistic roles, and comparative studies. She is the principal investigator of the Journalistic Role Performance (JRP) Project.Daniel C. Hallin is Distinguished Professor Emeritus at the University of California, San Diego. His books include, The "Uncensored War": The Media and Vietnam; "We Keep America on Top of the World": Television Journalism and the Public Sphere, Comparing Media Systems: Three Models of Media and Politics; and Making Health Public.