Practical guidance, based on rigorous research and informed by real world examples, describes the challenges of data management and provides the principles, strategies, tools, and techniques necessary to meet them. The authors, all leaders in the field of data quality for many years, discusses how to make the economic case for data quality and the importance of getting the leader of the organization on the board. They describe real problems and solutions, including efforts to find the root cause of the problem of data quality in a healthcare organization and data quality initiatives being undertaken by major teaching hospitals. They discuss setting company policy on data quality and, finally, they consider future challenges on the way to the quality of data.