# Conditional type I error rate (also called conditional rejection probability)

### Description

Calculates the conditional type I error rate of a GSD

### Usage

1 | ```
cer(pT, iD)
``` |

### Arguments

`pT` |
object of the |

`iD` |
interim data; a list with the variables |

### Value

cer conditional type I error rate

### Author(s)

Niklas Hack niklas.hack@meduniwien.ac.at and Werner Brannath werner.brannath@meduniwien.ac.at

### References

Mueller, HH, Schaefer, H (2001) ”Adaptive group sequential design for clinical trials: Combining the advantages of adaptive and of classical group sequential approaches”, *Biometrics*, 57, 886-891.

### See Also

`plan.GST`

### Examples

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