News media strongly influence how we picture public affairs across the world, playing a significant and sometimes controversial role in determining which topics are at the centre of public attention and action. Setting the Agenda, first published in 2004, has become the go-to textbook on this crucial topic. In this timely third edition, Maxwell McCombs - a pioneer of agenda-setting research - and Sebastián Valenzuela - a senior scholar of agenda setting in Latin America - have expanded and updated the book for a new generation of students. In describing the media's influence on what we think about and how we think about it, Setting the Agenda also examines the sources of media agendas, the psychological explanation for their impact on the public agenda, and their consequences for attitudes, opinions and behaviours. New to this edition is a discussion of agenda setting in the widened media landscape, including a full chapter on network agenda setting and a lengthened presentation on agenda melding. The book also contains expanded material on social media and the role of agenda setting beyond the realm of public affairs, as well as a foreword from Donald L. Shaw and David H. Weaver, the co-founders of agenda-setting theory. This exciting new edition is an invaluable source for students of media, communications and politics, as well as those interested in the role of news in shaping and directing public opinion.