In one embodiment, a processing technique is provided that utilizes multiple network address observations. One or more records are obtained that maintain network address observations, each network address observation associating one or more attributes with a network address observed by one or more source devices. Multiple network addresses from the network address observations are clustered into one or more discrete groups of network addresses based on a clustering criteria. For a selected group of network addresses, an association is formed associating one or more refined attributes derived from the selected group with an individual network address that is a member of the selected group.