  The cognitive research on reputation has shown several interesting properties
that can improve both the quality of services and the security in distributed
electronic environments. In this paper, the impact of reputation on
decision-making under scarcity of information will be shown. First, a cognitive
theory of reputation will be presented, then a selection of simulation
experimental results from different studies will be discussed. Such results
concern the benefits of reputation when agents need to find out good sellers in
a virtual market-place under uncertainty and informational cheating.
