Trust Definitions
Trust is a universal concept and has received attention from several disciplines. Below are a few definitions of trust as put forth by some researchers.
One of the most popular definition of trust is the one coined by Deutsch in 1962 which states that:
(a) an individual is confronted with an ambiguous path, a path that can lead to an event perceived to be beneficial or to an event perceived to be harmful; (b) he perceives that the occurrence of these events is contingent on the behavior of another person; and (c) he perceives the strength of a harmful event to be greater than the strength of a beneficial event. If he chooses to take an ambiguous path with such properties, he makes a trusting choice; else he makes a distrustful choice.
An interesting fact about the above definition pointed out by Marsh is that trust is considered to be subjective and dependent on the views of the individual. Deutsch further refined his definition of trust in 1973 as - confidence that an individual will find what is desired from another, rather than what is feared.
This definition is also echoed by the Webster dictionary which defines trust as - a confident dependence on the character, ability, strength, or truth of someone or something.
Luhmann [Luhmann, 1979] approaches trust sociologically and considers trust as - a means for reducing the complexity of society; complexity created by interacting individuals with different perceptions and goals. This definition because of its social nature is more apt for reputation-based systems.
Another popular definition of trust that has also been adopted by computer scientists is the one coined by Diego Gambetta [Gambetta, 1990]. He defines trust as - a particular level of the subjective probability with which an agent assesses that another agent or group of agents will perform a particular action, both before he can monitor such action (or independently of his capacity ever to be able to monitor it) and in a context in which it affects his own action. Gambetta introduced the concept of using values for trust and also defended the existence of competition among cooperating agents.
A recent definition of trust has been put forth by Grandison and Sloman [Grandison and Sloman, 2000] who define trust as - the firm belief in the competence of an entity to act dependably, securely, and reliably within a specified context.