Karma system

A Karma system, also known as a web reputation system is, at its most general, an automated or semiautomated method of characterizing online user behavior in a way useful to the particular venue. The term "reputation system" is broader than World Wide Web context alone, and draws from the distributed trust model used by Pretty Good Privacy to assess the reliability of cryptographic keys, and, indirectly, the reputation of their user. Closely related mechanisms may be used to detect spammers in electronic mail systems.

"There are three types of lies - lies, damn lies, and facts found on the Web." — Dr. Tim Finin, paraphrasing the well known quotation by Benjamin Disraeli on Statistics

Farmer and Glass have described some general terms for characterizing karma systems. First, a system may be public, with its findings immediately available to all or most users, or private, available only to administrators who control others' access. In all cases, the karma score is context-specific and should not be generalized to things beyond its capability, within the site or to other venues. They mention, as one example of overuse of a reputation, the FICO score for creditworthiness widely used in the United States, which has been controversially applied to such things as risk in granting insurance.