Steven A. Julious is a Professor of Medical Statistics at the University of Sheffield. His research interests include clinical trials, clinical trial design, early phase trials, and the development of new methodologies related to clinical trials.

1. Introduction. 2.Seven Key Steps to Cook up a Sample Size. 3. Sample Sizes for Parallel Group Superiority Trials with Normal Data. 4. Sample Size Calculations for Superiority Cross-Over Trials with Normal Data. 5. Sample Size for Cluster Randomized Trials. 6. Allowing for Multiplicity in Sample Sizes Calculations for Clinical Trials. 7. Samples Size Calculations for Non-Inferiority Clinical Trials with Normal Data. 8. Sample Size Calculations for Equivalence Clinical Trials with Normal Data. 9. Sample Size Calculations for Bioequivalence Trials. 1. Sample Size Calculations for Precision Clinical Trials with Normal Data. Sample Size for Pilot Studies. 12. Sample Size Calculations for Parallel Group Superiority Clinical Trials with Binary Data. 13. Sample Size Calculations for Superiority Cross-Over Clinical Trials with Binary Data. 14. Sample Size Calculations for Non-Inferiority Trials with Binary Data. 15. Sample Size Calculations for Equivalence Trials with Binary Data. 16. Sample Size Calculations for Precision Trials with Binary Data. 17. Sample Size Calculations for Single Arm Clinical Trials and Studies with Finite Population Size. 18. Sample Sizes for Clinical Trials with an Adaptive Design. 19. Sample Size Calculations for Clinical Trials with Ordinal Data. 20. Estimating the Number of Events for Clinical Trials with Survival Data for a Negative Outcome. 21. Sample Size Calculations for Clinical Trials with Survival Data and a Positive Outcome. 22. Sample Size Calculations for Clinical Trials with Survival Data Allowing for Recruitment and Withdrawal. 23. Appendix. 24. References.