On construction of Symmetrical and Asymmetrical Fractional Factorials

Abstract

This thesis contains two parts. In the first part a method of construction of symmetrical fractional factorials with blocking for factors each at three levels is given. The method is illustrated with an example. In the appendix a number of plans of various such designs from 7 factors to 15 factors using blocks of size 4 and 9 have been presented. The block only of each design is given indicating the method of obtaining the rest of the blocks of the designs. In the second part few methods of construction of asymmetrical fractional factorial designs are given with illustrations. Also a measure of dependence between any two affected interaction components of an asymmetrical fraction is discussed and the results verified through a particular example. Using the above technique an interaction of interest can be estimated after adjusting it for the effect of any other interaction mixed with it.