At the center of debates on deliberative democracy is the issue of how much deliberation citizens experience in their social networks. These “disagreements about disagreement” come in a variety of forms, with scholars advocating different empirical approaches (e.g., Huckfeldt, Johnson, and Sprague 2004; Mutz 2006) and coming to different substantive conclusions. We address these discrepancies by going back to the basics: investigating the consequences of conceptual and measurement differences for key findings relating interpersonal political disagreement to political attitudes and behaviors. Drawing on the 2008–2009 ANES panel study, we find evidence that different measures of disagreement have distinct effects when it comes to individuals’ preferences, patterns of engagement, and propensities to participate. We discuss the implications for the study of social influence; as interpersonal disagreement can mean different things, scholars should think carefully about how to study it and should exercise caution when making pronouncements about its empirical and democratic consequences.