Along with the rise of credit card use, fraud is on the rise. To address fraud, financial institutions (FIs) are employing fraud detection systems (FDS),however, the majority of cases being flagged by this system are False Positives. The possibilities of enhancing the current operation by post processing the FDS output constitute the objective of this book. The data used for the analysis was provided by one of the major Canadian banks. Based on several variations and combinations of features and training class distributions, different models(more than seventy) were developed to explore the