Monitoring Data Quality for Very High Volume Transaction Systems * Joseph Bugajski Visa International Robert L. Grossman † Open Data Group Eric Sumner Open Data Group Steve Vejcik Open Data Group July 7, 2006 This is a draft of the paper Joseph Bugajski, Robert L. Gross- man, Eric Sumner and Steve Vejcik, Monitoring Data Quality for Very High Volume Transaction Systems, Proceedings of the 11th International Conference on Information Quality, 2006. Abstract In this paper we describe a new methodology for detecting data quality problems in high volume transaction streams called change detection using cubes of models or CDCM. We also describe how this system is deployed at Visa and two case studies that occurred during its first year of operation. * This work was supported in part by the Visa International Data Interoperability Program and the U.S. Army Pantheon Project. † Robert Grossman is the corresponding author. He is also a faculty member at the University of Illinois at Chicago. 1