Emerging as a discipline in the first half of the twentieth century, the information sciences study how people, groups, organizations, and governments create, share, disseminate, manage, search, access, evaluate, and protect information, as well as how different technologies and policies can facilitate and constrain these activities. Given the broad span of the information sciences, it is perhaps not surprising that there is no consensus regarding its underlying theory-the purposes of it, the types of it, or how one goes about developing new theories to talk about new research questions. Diane H. Sonnenwald and the contributors to this volume seek to shed light on these issues by sharing reflections on the theory-development process. These reflections are not meant to revolve around data collection and analysis; rather, they focus on the struggles, challenges, successes, and excitement of developing theories. The particular theories that the contributors explore in their essays range widely, from theories of literacy and reading to theories of design and digital search. Several chapters engage with theories of the behavior of individuals and groups; some deal with processes of evaluation; others reflect on questions of design; and the rest treat cultural and scientific heritage. The ultimate goal, Sonnenwald writes in her introduction, is to "encourage, inspire, and assist individuals striving to develop and/or teach theory development."