Download a copy of the VA User Guide.

Questions? Comments? Please submit them via the VA discussion forum.

Click here to learn how to calculate statistical power for cluster randomized trials utilizing the VA ICCs, or consult the VA User Guide.

Select your sample

Please use the following menus to select the sample most appropriate to your study population.

To begin the process, identify the subject matter of interest. You then will be prompted to provide additional information on the region, urbanicity, any special sub-sample characteristics, the grade level, and the data source. Note: this information must be entered sequentially, using the drop-down menus below. The 'submit' key must be clicked after each selection has been made for the next menu to appear.

When the selection process is complete, results will be displayed in a table on screen that can be printed using your browser's 'print' function.

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