GroupSeq menu
Loading the library opens the main GroupSeq window.
library("GroupSeq")
The menu lists four possible tasks. To select a task, you have to select a row and hit the Perform Selected Task button. Each task opens in a new window and it's also possible to open multiple windows of the same task in parallel. For a detailed description of the respective task follow one of the links below:
-1- Compute Bounds
Use this to compute the boundaries of group sequential designs under the null hypothesis (H0), that is, under a given significance level alpha (usually 5%).
- Computes group sequential bounds under the null hypothesis for given overall significance level.
- Bounds can be one- or two-sided or completely asymmetric.
- User chooses number of stages and some alpha spending function.
-2- Compute Drift given Power and Bounds
Use this to compute the target effect size of a group sequential design, which maintains a certain power (e.g. power = 80%).
- Computes drift (i.e. standardized effect size) required to achieve desired power of a given group sequential design.
- The group sequential design is defined via alpha spending functions or custom critical bounds.
- Bounds can be one- or two-sided or completely asymmetric.
- User chooses number of stages.
-3- Compute Probabilities given Bounds and Drift
Use this to compute the power of a group sequential design.
- Computes power that is achieved by a group sequential design given some drift (i.e. standardized effect size).
- The group sequential design is defined via alpha spending functions or custom critical bounds.
- Bounds can be one- or two-sided or completely asymmetric.
- User chooses number of stages.
-4- Compute Confidence Interval
Use this to compute the confidence intervals for the target outcome at the final analysis, which can be the last stage as planned or at an earlier stage exceeding the critical bounds and therefore stopping early.
- Computes confidence interval at final analysis stage for given expected effect size.
- The group sequential design is defined via alpha spending functions or custom critical bounds.
- Bounds can be one- or two-sided or completely asymmetric.
- User chooses number of stages and confidence level.
To close the application and, with it, all open windows, just close the main window or hit the QUIT GroupSeq button.