IntroductionThis chapter discusses the notion of trust as it relates to information science and technology, specifically user interfaces, autonomous agents, and information systems. We first present a n in-depth discussion of the concept of trust in and of itself, moving on to applications and considerations of trust in relation to information technologies. We consider trust from a "soft" perspective-thus, although security concepts such as cryptography, virus protection, authentication, and so forth reinforce (or damage) the feelings of trust we may have in a system, they are not themselves constitutive of ''trust." We discuss information technology from a human-centric viewpoint, where trust is a less well-structured but much more powerful phenomenon.With the proliferation of electronic commerce (e-commerce) and the World Wide Web (WWW, or Web), much has been made of the ability of individuals to explore the vast quantities of information available to them, to purchase goods (as diverse as vacations and cars) online, and to publish information on their personal Web sites. Now that the hyperbole 465 466 Annual Review of Information Science and Technology has died down somewhat and the situation is beginning to stabilize, we wish to examine one of the more important aspects of this "information revolution": the concept of trust. Although always simmering in the background of the social sciences literature, especially over the past decade in management, the study of trust has moved center stage in the world of online information and direct interaction (see, for example, Marsh, Meech, & Dabbour, 2000;Palmer, Bailey, & Faraj, 2000; Rosenbloom, 2000b;Urban, Sultan, & Qualls 1999).Thus, a n understanding of trust's role and impact is crucial for information systems practitioners and researchers; the main purpose of this review is to provide such a n understanding. The chapter is primarily aimed at management scientists with a n interest in social informatics, designers with a n interest in social phenomena, and other similar readers. However, they will be disappointed if they expect a study of a broad range of social interactionist influences, such as social capital (e.g., Lesser, 2000), authenticity and credibility (e.g., Council on Library and Information Resources, 20001, authority (e.g., Wilson, 19831, knowledge management (e.g., Davenport & Cronin, 20001, and communities of practice (e.g., Prusak & Cohen, 2000;Wenger, 1998Wenger, ,2000, to name but a few. Each of these has a quite separate theoretical base, even if they appear ostensibly similar to the lay reader; a review encompassing such a broad range of influences is beyond our scope.Trust has been the topic of considerable study in the social sciences for many years. As such, the chapter consists of a number of sections designed to enable the reader to acquire (1) a broader understanding of how trust operates as a social and interactional phenomenon and, based on this, (2) a more specific understanding of where trust fits into research and practice in inf...