In this overview we introduce the basic ideas behind a new flexible approach in sequential
designs. The different concepts based on two-stage combination tests and conditional
error functions are brought together. We sketch the construction of p-values, confidence
intervals, and median unbiased estimates. Finally, recursive combination tests are
introduced which extend the flexibility to the choice of the number of interim analyses.
Keywords
Adaptive Design - Midtrial Design Modification - Two-stage Combination Test - Conditional
Error Function - Confidence Interval - Recursive Combination Test