A system and method for determining relevancy for dynamic data sets is disclosed. A specific embodiment for use in an internet marketplace is presented wherein the relevancy for a descriptive factor associated with an item is increased when a user selects that item. To prevent abuse of the relevancy determination system, various embodiments incorporate abuse prevention measures. In one embodiment, a user's selection of the user's own items does not affect the relevancy system. In one embodiment, only a first selection of a particular item by a user will affect the relevancy system and any additional selections of that item will have no effect. In another embodiment, the size of the changes made due to the selections of particular user to the relevancy system are correlated to that user's reputation score.