ANOVA power dialog for a split-plot design

This GUI (separate window) may be used to study power and sample-size problems for a split-plot design in two primary factors wp (the whole-plot or between-subjects factor) and sp (the subplot or within-subjects factor). In this design, each BLOCK (considered a random factor) is divided into plots, and levels of wp are assigned to plots. Each plot is divided into subplots, and levels of sp are assigned to subplots. Note that a plot is identified with a BLOCK*wp combination, which in turn serves as a blocking factor for sp.

A design without the top-level blocking is available as a "nested factorial" design.


Click or drag on the bar graphs to adjust values; or enter values in the text areas and hit RETURN. (Power values are not adjustable.) You can change the scales for the bar graphs by dragging from any point along the scale to its desired new position -- provided that this would not cause a bar to go out-of-bounds.

Feedback is welcome!
Russell V. Lenth (rlenth@stat.uiowa.edu), Department of Statistics and Actuarial Science, The University of Iowa, Iowa City, IA 52245