Trust metric
From Wikipedia, the free encyclopedia
In psychology and sociology, a trust metric is a measurement of the degree to which a members of a group is trusted by each other. Trust metrics may be abstracted in a manner that can be implemented on computers, making them of interest for the study and engineering of virtual communities, such as Friendster and LiveJournal. Attack resistance is an important property of trust metrics which reflects their ability not to be overly influenced by agents who try to manipulate the trust metric and who participate in bad faith (i.e. who aim to abuse the presumption of trust).
The first commercial forms of trust metrics in computer software were in applications like eBay's Feedback Rating. Slashdot introduced its notion of karma, earned for activities perceived to promote group effectiveness, an approach that has been very influential in later virtual communities.
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[edit] Properties of trust metrics
[edit] Transitivity
Another formal trust metric and trust model is that of subjective logic which in addition to trust levels includes the ability to express ownership (subjectivity) and degrees of uncertainty. A fundamental property of this model is that trust is diluted, i.e. becomes more uncertain, through transitivity[1]. This metric is used in some online communities like e.g. Rummble.com.
Recently, researchers have shown that trust transitivity does not always hold and, consequently, have proposed new trust metrics[2].
[edit] Attack resistance
The free software developer resource Advogato is based on a novel approach to attack-resistant trust metrics of Raph Levien. Levien observed that Google's PageRank algorithm can be understood to be an attack resistant trust metric rather similar to that behind Advogato. Despite the trust metric, posting privileges to the front page of Advogato[3] have been gained by an individual notorious for his self-proclaimed but discredited[4] claim to be an "AI theorist",[5] illustrating just how complex the problem of trust is.
[edit] Evaluation of work on trust metrics
Trust Metrics Wiki is a Wiki whose goal is to review, understand, code and compare on same data all the trust metrics proposed so far.
Trust metrics are closely related to reputation systems.
[edit] See also
[edit] References
- ^ A. Jøsang, R. Hayward, S. Pope. Trust Network Analysis with Subjective Logic. Proceedings of the Australasian Computer Science Conference (ACSC'06), Hobart, January 2006. [PDF]
- ^ D. Quercia, S. Hailes, L. Capra. Lightweight Distributed Trust Propagation. ICDM'07.
- ^ Advogato: Mentifex on AI ethical decisions of life and death in artificial intelligence
- ^ An anonymous edit inserted "allegedly" before "discredited", and stated there is no source (basis) for stating that the individual referred to is discredited. In point of fact there is a source, which is cited in a subsequnt note. This is characteristic of this individual – to miss the obvious and persist in puerile argument. That "Mentifex" is totally discredited in the field of AI is thoroughly documented in the source cited (Mentifex_FAQ). In particular see section 2.3, "What do researchers in academia think of Murray’s work?"
- ^ See the Mentifex_FAQ, and this article's Talk Page regarding repeated and anonymous attempts to delete this section.
[edit] External links
- Trust Metrics Evaluation Project of Paolo Massa. TheAnalyzed Trust Metrics page provides an extensive bibliography of work on the theory and implementation of trust metrics.
- Trustcomp.org is an online community of more than 150 academic and industrial members who research computational trust management and online reputation. There is also a mailing list.
- Online demonstrations of subjective logic.
- Raph Levien, 2000. Advogato's trust metric. Electronic manuscript.
- Raph Levien, 2002. Attack Resistant Trust Metric Metadata HOWTO. Electronic manuscript.
- Trust Metrics - by P2P Foundation
- Rummble - Recommendations engine based on trust networking, including a Trust Network API for 3rd parties
