- In collaborative information finding systems, evaluations provided by users assist other users with similar needs. This article examines the problem of getting users to provide evaluations, thus overcoming the so-called “free-riding” behavior of users. Free riders are those who use the information provided by others without contributing evaluations of their own. This article reports on an experiment conducted using the “AntWorld,” system, a collaborative information finding system for the Internet, to explore the effect of added motivation on users' behavior. The findings suggest that for the system to be effective, users must be motivated either by the environment, or by incentives within the system. The findings suggest that relatively inexpensive extrinsic motivators can produce modest but significant increases in cooperative behavior.