The document discusses metrics that are useful for planning and evaluating e-discovery projects, including source gigabytes per project, types of source media, de-duplication levels, custodians per project, percentage of data that is email, reviewers per project, gigabytes produced per project, and ratio of pages reviewed to produced. It then provides charts and analysis on trends in these metrics based on data from nearly 4,000 e-discovery cases over six years, finding that source data sizes and de-duplication levels are increasing while custodians, reviewers, and data produced per project are decreasing.