All, I understand the concept of peak-to-peak heights in the design.mat file. The PPheights values in our design.con, however, are inconsistent. How is PPheights calculated in design.con? Similarly, what exactly is RequiredEffect, and how is it cacluated? I assume it is the t value that would be necessary to achieve a significant effect. Thank you in advance for any guidance you can provide. William E. Janes Research Assistant Head Research Laboratory Washington University in St. Louis