Trust is a judgement of unquestionable utility — as humans we use it every day of our lives. However, trust has suffered from an imperfect understanding, a plethora of definitions, and informal use in the literature and in everyday life. It is common to say “I trust you, ” but what does that mean? This thesis provides a clarification of trust. We present a formalism for trust which provides us with a tool for precise discussion. The formalism is implementable: it can be embedded in an artificial agent, enabling the agent to make trust-based decisions. Its applicability in the domain of Distributed Artificial Intelligence (DAI) is raised. The thesis presents a testbed populated by simple trusting agents which substantiates the utility of the formalism. The formalism provides a step in the direction of a proper understanding and definition of human trust. A contribution of the thesis is its detailed exploration of the possibilities of future work in the area. Summary 1. Overview This thesis presents an overview of trust as a social phenomenon and discusses it formally. It argues that trust is: • A means for understanding and adapting to the complexity of the environment. • A means of providing added robustness to independent agents. • A useful judgement in the light of experience of the behaviour of others. • Applicable to inanimate others. The thesis argues these points from the point of view of artificial agents. Trust in an artificial agent is a means of providing an additional tool for the consideration of other agents and the environment in which it exists. Moreover, a formalisation of trust enables the embedding of the concept into an artificial agent. This has been done, and is documented in the thesis. 2. Exposition There are places in the thesis where it is necessary to give a broad outline before going deeper. In consequence it may seem that the subject is not receiving a thorough treatment, or that too much is being discussed at one time! (This is particularly apparent in the first and second chapters.) To present a thorough understanding of trust, we have proceeded breadth first in the introductory chapters. Chapter 3 expands, depth first, presenting critical views of established researchers.

At any given time, the stability of a community depends on the right balance of trust and distrust. Furthermore, we face information overload, increased uncertainty and risk taking as a prominent feature of modern living. As members of society, we cope with these complexities and uncertainties by relying trust, which is the basis of all social interactions. Although a small number of trust models have been proposed for the virtual medium, we find that they are largely impractical and artificial. In this paper we provide and discuss a trust model that is grounded in real-world social trust characteristics, and based on a reputation mechanism, or word-of-mouth. Our proposed model allows agents to decide which other agents' opinions they trust more and allows agents to progressively tune their understanding of another agent's subjective recommendations.

whether we necessarily need more cooperation, keeping, for the moment, the distinction between cooperation and trust blurred and their relationship implicit. According to the trite observation - Adam Smith wrote - if there is any society among robbers and murderers, they must at least abstain from robbing and murdering one another (Smith [1759] 1976: 86; see also Saint Augustine in Dunn, this volume). This trite observation serves a double purpose: it reminds us that basic forms of cooperation are inevitable if a society is to be at all viable, but it also points out, perhaps unwittingly, that there are instances of cooperation - notably those among robbers and murderers - that we may want to dispose of rather than improve. We may want less cooperation (and trust) rather than more, especially among those who are threatening us, and whose cooperation is a hindrance to ours. A priori, we cannot always say whether greater trust and cooperation are in fa

Davis, Gerald Smith and Aks Zaheer for their helpful reviews and comments on earlier versions of this paper. Trust is a key enabler of cooperative human actions. Three main deficiencies about our current knowledge of trust are addressed by this paper. First, due to widely divergent conceptual definitions of trust, the literature on trust is in a state of construct confusion. Second, too little is understood about how trust forms and on what trust is based. Third, little has been discussed about the role of emotion in trust formation. To address the first deficiency, this paper develops a typology of trust. The rest of the paper addresses the second and third deficiencies by proposing a model of how trust is initially formed, including the role of emotion. Dispositional, interpersonal, and impersonal (system) trust are integrated in the model. The paper also clarifies the cognitive and emotional bases on which interpersonal trust is formed in early relationships. The implications

Our trust conceptualizations have benefited from discussions with Ellen Berscheid and Larry Cummings of the University of Minnesota. The authors also thank three anonymous reviewers from the Organizational Behavior division of the 1996 meeting of the Academy of Management for their comments on an earlier version of this paper. THE MEANINGS OF TRUST What does the word ‘trust ’ mean? Scholars continue to express concern regarding their collective lack of consensus about trust’s meaning. Conceptual confusion on trust makes comparing one trust study to another problematic. To facilitate cumulative trust research, the authors propose two kinds of trust typologies: (a) a classification system for types of trust, and (b) definitions of six related trust types that form a model. Some of the model’s implications for management are also outlined. 2 THE MEANINGS OF TRUST “...trust is a term with many meanings. ” (Williamson, 1993: 453) “Trust is itself a term for a clustering of perceptions. ” (White, 1992: 174) Scholars and practitioners widely acknowledge trust's importance. Trust makes cooperative endeavors happen (e.g., Arrow, 1974; Deutsch, 1973; Gambetta, 1988). Trust is a key to positive interpersonal relationships in

What kinds of social relationships can people have with computers? Are there activities that computers can engage in that actively draw people into relationships with them? What are the potential benefits to the people who participate in these human-computer relationships? To address these questions this work introduces a theory of Relational Agents, which are computational artifacts designed to build and maintain long-term, social-emotional relationships with their users. These can be purely software humanoid animated agents--as developed in this work--but they can also be non-humanoid or embodied in various physical forms, from robots, to pets, to jewelry, clothing, hand-helds, and other interactive devices. Central to the notion of relationship is that it is a persistent construct, spanning multiple interactions; thus, Relational Agents are explicitly designed to remember past history and manage future expectations in their interactions with users. Finally, relationships are fundamentally social and emotional, and detailed knowledge of human social psychology--with a particular emphasis on the role of affect--must be incorporated into these agents if they are to effectively leverage the mechanisms of human social cognition in order to build relationships in the most natural manner possible. People build

F14.33> Gemeinschaft. It does not give any new insight into the particularities of trusting relations. To gain such insights we need further conceptual clarification. Bernard Barber at least perceives this need. In his recent monograph The Logic and Limits of Trust (1983; see also Barber 1985) he tries for the first time to provide some kind of ordering. He proposes to distinguish between three different dimensions in which trusting expectations may fail: the continuity of the natural and the moral order, the <<95>> technical competence of actors in roles, and the fiduciary obligations of actors, that is, their duty and their motives to place the interests of others before their own. This distinction refers to the content of expectations and, indirectly, to causes of disappointment. It leaves unspecified, however, the social mechanisms which generate trust in spite of possible disappointment. It is this question, and in a more general sense the problem of the<F

ABSTRACT: Trust is a vital relationship concept that needs clarification because researchers across disciplines have defined it in so many different ways. A typology of trust types would make it easier to compare and communicate results, and would be especially valuable if the types of trust related to one other. The typology should be interdisciplinary because many disciplines research e-commerce. This paper justifies a parsimonious interdisciplinary typology and relates trust constructs to e-commerce consumer actions, defining both conceptual-level and operational-level trust constructs. Conceptual-level constructs consist of disposition to trust (primarily from psychology), institution-based trust (from sociology), and trusting beliefs and trusting intentions (primarily from social psychology). Each construct is decomposed into measurable subconstructs, and the typology shows how trust constructs relate to already existing Internet relationship constructs. The effects of Web vendor interventions on consumer behaviors are posited to be partially mediated by consumer trusting beliefs and trusting intentions in the e-vendor. KEY WORDS AND PHRASES: Customer relationships, human issues in e-commerce, Internet consumers, trust.

Automation is often problematic because people fail to rely upon it appropriately. Because people respond to technology socially, trust influences reliance on automation. In particular, trust guides reliance when complexity and unanticipated situations make a complete understanding of the automation impractical. This review considers trust from the organizational, sociological, interpersonal, psychological, and neurological perspectives. It considers how the context, automation characteristics, and cognitive processes affect the appropriateness of trust. The context in which the automation is used influences automation performance and provides a goal-oriented perspective to assess automation characteristics along a dimension of attributional abstraction. These characteristics can influence trust through analytic, analogical, and affective processes. The challenges of extrapolating the concept of trust in people to trust in automation are discussed. A conceptual model integrates research regarding trust in automation and describes the dynamics of trust, the role of context, and the influence of display characteristics. Actual or potential applications of this research include improved designs of systems that require people to manage imperfect automation.

We propose a new theoretical framework for understanding simultaneous trust and distrust within relationships. grounded in assumptions of multidimensionality and the inherent tensions of relationships. and we separate this research from prior work grounded in assumptions of unidimensionality and balance. Drawing foundational support for this new framework from recent research on simultaneous positive and negative sentiments and ambivalence. we explore the theoretical and practical significance of the framework for future work on trust and distrust relationships within organizations.