Symmetric group sequential test designs.

1. Summary: The 1989 article describing the symmetric group sequential designs and the robustness of those designs to altered schedule of analyses
   

2. Ref: Emerson SS, Fleming TR, Biometrics 45: 905-923 (1989).
   

A unifying family of group sequential tests designs.

1. Summary: The 1999 article describing the unified family of group sequential test designs and the algorithm for fitting four separate boundary shapes.
   

2. Ref: Kittelson JM, Emerson SS, Biometrics 55: 874-882 (1999).
   

Implementing type I & type II error spending for two-sided group sequential designs.

1. Summary: A comparison of two methods of implementing the "wedge type" two-sided stopping rules.
   

2. Ref: Rudser KD, Emerson SS (2007), Contemporary Clinical Trials 29: 351-358 (2008).
   

Frequentist evaluation of group sequential clinical trial designs

1. Summary: A tutorial on the various operating characteristics of interest when choosing a group sequential stopping rule.
   

2. Ref: Emerson SS, Kittelson JM, Gillen DL, Statistics in Medicine 26: 5047-5080 (2007).
   

On the Use of Stochastic Curtailment in Group Sequential Clinical Trials

1. Summary: A discussion of conditonal power and predictive power in monitoring RCT.
   

2. Ref: Emerson SS, Kittelson JM, Gillen DL, (BEPress) (2005)
   
   

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