In one embodiment, a filtering technique is provided for ensuring data quality of network address observations. A network address observation is obtained of a network address associated with a source device, the network address observation associating the network address with one or more directly observed attributes. The network address observation is filtered based on a comparison of a selected one of the one or more directly observed attributes to a predetermined criteria, and using a result of the comparison as indicative of whether the network address observation should be used for association of the network address with one or more directly observed attributes. The filtering either associates one or more indicators with the network address observation, or removes the network address observation. A network address to attribute association system executed on one or more electronic devices stores a record that maintains any network address observation that has not been removed and any indicator.