How much trust is enough to trust? A market-adaptive trust threshold setting for e-marketplaces

The inherent uncertainties of open marketplaces motivate the design of reputation systems to facilitate buyers in finding honest feedback from other buyers (advisers). Defining the threshold for an acceptable level of honesty of advisers is very important, since inappropriately set thresholds would filter away possibly good advice, or the opposite - allow malicious buyers to badmouth good services. However, currently, there is no systematic approach for setting the honesty threshold. We propose a self-adaptive honesty threshold management mechanism based on PID feedback controller. Experimental results show that adaptively tuning the honesty threshold to the market performance enables honest buyers to obtain higher quality of services in comparison with static threshold values defined by intuition and used in previous work.