This chapter includes articles representing three of the most commonly used kinds of nonreactive research: content analysis, accretion measures, and the use of existing data. Content analysis is an approach that examines written, visual, or spoken text. Accretion measures are techniques in which researchers systematically examine things that people leave behind that can yield insights into their behaviors, attitudes, and values. Sorensen and his colleagues neatly illustrate some of the distinctive advantages and disadvantages of using existing data, including official statistics. Existing data are the best kind for addressing the research question. Because nonreactive research methods do not often involve humans directly, they allow researchers to avoid some of the ethical problems related to privacy and avoiding harm to participants. Sorensen also raises particularly troubling questions about the possible consequences of research findings related to the death penalty.