Towards the Next Generation of Computational Trust and Reputation Models

The scientific research in the area of computational trust and reputation mechanisms for virtual societies is a recent discipline oriented to increase the reliability and performance of electronic communities by introducing in such communities these well known human social control mechanisms. Computer science has moved from the paradigm of an isolated machine to the paradigm of a network of systems and of distributed computing. Likewise, artificial intelligence is quickly moving from the paradigm of an isolated and non-situated intelligence to the paradigm of a situated, social and collective intelligence. This new " social " dimension is the main responsible of the increasing interest on computational trust and reputation mechanisms applied to electronic societies. Computational trust and reputation systems have been recognized as key factors for successful electronic commerce adoption. These systems are used by intelligent software agents both as a mechanism of search for trustworthy exchange partners and as an incentive in decision-making about whether or not to honour contracts. Reputation is also used in electronic markets as a trust-enforcing, deterrent , and incentive mechanism to avoid cheaters and frauds. Another area of application in agent technology is teamwork and cooperation. However, in spite of the obvious utility of using a trust and reputation system, they are still not a usual element you can find in an agent architecture like it is the case for example of planners or communication modules. Trust and reputation systems still belong to the set of " not so important " elements of an agent architecture. This is something it has to change if we really want artificial socially intelligent entities. If we analyze which computational trust and reputation models are used nowadays, we will notice that only the simplest models are really used (see for example e-Bay[1]). Till now, the use of complex trust and reputation models has been somehow questioned and reduced to academic environments. Why an artificial agent has to use one of these complex models if it is evolving in a simple community with 10 or 15 agents that have limited interaction capabilities? In other words, the applications and environments are too simple to justify a complex trust and reputation model that only has sense in a socially complex environment. However this situation is changing very quickly. The increase of the global connectivity (everything is interconnected anytime and everywhere) is bringing us a new concept of environment where virtual entities need …