The United States Sentencing Commission (USSC) collected and analyzed data on guideline sentences to support its varied activities. As authorized by Congress, the Commission’s research responsibilities include: (1) the establishment of a research and development program to serve as a clearinghouse and information center for the collection, preparation, and dissemination of information on federal sentencing practices; (2) the publication of data concerning the sentencing process; (3) the systematic collection and dissemination of information concerning sentences actually imposed and the relationship of such sentences to the factors set forth in section 3553(a) of Title 18, United States Code; and (4) the systematic collection and dissemination of information regarding the effectiveness of sentences imposed. For each case in its Offender Dataset, the Commission routinely collected case identifiers, sentencing data, demographic variables, statutory information, the complete range of court guideline decisions, and departure information. The Commission’s 2000 USSC Offender Dataset contains documentation on 59,846 cases sentenced under the Sentencing Reform Act between October 1, 1999, and September 30, 2000. A “case” is defined as one sentencing event for an individual defendant. The Organizational Dataset captures information on organizations sentenced under Chapter Eight of the guidelines. The data collected describes organizational structure, size, and economic viability; offense of conviction; mode of adjudication; sanctions imposed; and application of the sentencing guidelines. The Commission received information on 304 organizations that were sentenced under Chapter Eight of the sentencing guidelines in 2000. The Appeals Dataset tracked appellate review of sentencing decisions. Information captured in this module included district, circuit, dates of appeal and opinion, legal issues, and the court’s disposition. In addition to its standard data collection, the Commission often codes additional information to study as discrete variables (e.g., immigration offenses, child sex offenses). The Commission also tracked final opinions and orders, both published and unpublished, in federal criminal appeals. During 2000, the Commission supplemented these opinions and orders with cases available on computerized legal databases and with habeas corpus decisions because such cases often involve sentencing issues. In 2000, the Commission gathered information on 6,381 appellate cases of which 2,341 were “conviction only” cases. Figures, tables, and appendixes