Design-Expert 7.1 features upfront power calculation for factorial designs, providing the probability of seeing a desired difference (the signal) in a measured response given the amount of noise in the process, which could avoid pressing ahead with a lost cause if there is excessive variability in the process and/or test. Other features include a fraction of design space graph that displays scaled prediction variance and a display of grid lines on 3D graph back planes, which provide a good perspective on the varying height of a response surface.
Stat-Ease Inc., Minneapolis, MN; 612-378-9449; www.statease.com
