INTRODUCTION; A Brief History of Clinical Trials; The Southwest Oncology Group; Example Trials; The Reason for the Book; STATISTICAL CONCEPTS; Introduction; The Phase II Trial-Estimation; The Phase III Trial-Hypothesis Testing; The Proportional Hazards Model; Sample Size Calculations; Concluding Remarks; THE DESIGN OF CLINICAL TRIALS; Introduction; Endpoints; Phase I Trials; Phase II Trials; Phase III Trials; Conclusion; MULTI-ARM TRIALS; Introduction; Types of Multi-Arm Trials; Significance Level; Power; Interaction; Other Model Assumptions; To Screen or Not to Screen; Timing of Randomization; Conclusion; INTERIM ANALYSIS AND DATA MONITORING COMMITTEES; Planned Interim Analysis; Data Monitoring Committees: Rationale and Responsibilities; Monitoring Committees: Composition; Examples; Concluding Remarks; DATA MANAGEMENT AND QUALITY CONTROL; Introduction: Why Worry?; Protocol Development; Data Collection; Protocol Management and Evaluation; Quality Assurance Audits; Training; Data Base Management; Conclusion; Appendix: Examples; REPORTING OF RESULTS; Timing of Report; Required Information; Analyses; Conclusion; PITFALLS; Introduction; Historical Controls; Competing Risks; Outcome by Outcome Analyses; Subset Analyses; Surrogate Endpoints; EXPLORATORY ANALYSES; Introduction; Some Background and Notation; Identification of Prognostic Factors; Forming Prognostic Groups; Analysis of Microarray Data; Meta-Analysis; Concluding Remarks; SUMMARY AND CONCLUSIONS