This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book begins with William McGuire's overview of half a century of voting studies. Famous for imposing order on scientific disarray, McGuire maps the continuities and discontinuities in the history of election research. It offers a critical assessment of their theoretical and methodological achievements, failings, and prospects. The book also offers new insights into the workings of the four major sources of influence that have underlain empirical voting research from the beginning: demographics, parties, issues, and media. It addresses the role of the media in election campaigns. The book focuses on Jay Blumler and Denis McQuail how mediated information is used by different kinds of voters. It asserts that election studies are too often disconnected from the political system in which the actual decisionmaking and voting are embedded.