1. A computerized method for visually modifying a rule comprising: receiving a rule and a plurality of data records, said rule comprises a plurality of computation instructions for each of said plurality of data records and each one of said plurality of data records comprising at least one physical location value; displaying a simulation comprising a plurality of visual objects, each of said plurality of visual objects showing a result of applying said rule to one of said plurality of data records, and displayed on a computerized display at a position representing said at least one physical location value corresponding to said one of said plurality of data records; receiving at least one marking from a user of at least one of said plurality of visual object on said computerized display to indicate a user desired adjustment in said results of applying said rule; modifying said plurality of computation instructions to produce a modified rule, based on said at least one marking; and sending said modified rule.