This article examines the use KDD, which makes it possible to create longitudinal data files from administrative data sources, extract valuable knowledge, and make the information available via a user-friendly public Web site. The article demonstrates a successful project in North Carolina where knowledge discovery and data mining technology are used to develop a comprehensive set of child welfare outcomes available through a public Web site to facilitate information sharing of child welfare data to improve policy and practice. Discussion is provided on data preparation; descriptive modeling; presentation and visualization; usability and training; maintenance and update; and development and funding. The authors note that proper management and implementation of an effective child welfare agency requires the constant use of information about the experiences and outcomes of children involved in the system, emphasizing the need for comprehensive, timely, and accurate data. Additionally of note is that in the past 20 years, there have been many advances in technology that can maximize the potential of administrative data to promote better evaluation and management in the field of child welfare. Figures, table, and references