Systems and techniques for characterizing a similarity between first and second data objects are described. A system includes a matching engine configured to receive first and second results provided by first and second attribute-matching strategies. The matching engine is further configured to scale the first result by a first weight factor that indicates a first level of quality of a first attribute value and to scale the second result by a second weight factor that indicates a second level of quality of a second attribute value. The matching engine is further configured to combine the first and second scaled results to produce an overall result characterizing the similarity between the first and second objects.