Online communities have something in common: their success rise and fall with the participation rate of active users. In this paper we focus on social rewarding mechanisms that generate benefits for users in order to achieve a higher contribution rate in a wiki system. In an online community, social rewarding is in the majority of cases based on accentuation of the most active members. As money cannot be used as a motivating factor others like status, power, acceptance, and glory have to be

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... oyed. We explain different social rewarding mechanisms which aim to meet these needs of users. Furthermore, we implemented a number of methods within the MediaWiki system, where social rewarding criteria are satisfied by generating a ranking of most active members.