Title:  Construction of Optimal Screening Designs from Hadamard Matrices

Presenter:  Dr. Debra Ingram, Arkansas State University

Fractional factorial designs are used in a wide variety of industrial and scientific investigations, where time and resources are always limited, and, as a result, run size economy and run size flexibility are important issues.  Regular fractional factorial designs are among the most widely used statistical experimental strategies for studying the effects of several variables simultaneously and are readily available in the literature.  However, they are limited in that the number of experimental runs must be a power of two, leaving large gaps in the available run sizes.  Nonregular fractional factorial designs taken from Hadamard matrices can be constructed for every run size that is a multiple of four, providing a distinct advantage over the regular designs.  This talk focuses on the use of computationally efficient search algorithms applied to Hadamard matrices for the construction of optimal nonregular designs.  The new designs compare favorably with the competing regular designs and make it possible for engineers and scientists to plan experiments for many different combinations of run size and number of variables to be studied.