Abstract: A multi-pass algorithm identifies duplicative information and correlates higher confidence and/or selected primary information in distributed databases. One embodiment determines a bounded area based at least in part on location information and/or location tolerances for a location-dependent attribute and comparing the bounded areas to previously indexed location information using a multi-pass algorithm to identify duplicative information. The algorithm may also use textual tolerances, confidence levels, and other factors to determine what information is to be correlated with the option of elevating the correlated information to a higher level database.