Trust metric

In psychology and sociology, a trust metric is a measure of how a member of a group is trusted by the other members. Trust metrics may be abstracted in a manner that can be implemeted 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 to handle agents who participate in bad faith (i.e. who aim to abuse the presumption of trust).

The first 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, that has been very influential in later virtual communities.

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. Levien also proposes a trust metric for Wikipedia to aid quality control and to minimize the effects of Vandalism.

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.

(I put some more content on the "Talk" page. If someone reads this and approves of it, just go ahead and move it here.)