Optimal blocking schemes in design experiments

Blocking is commonly used in design of experiments theory to reduce systematic noise and increase precision of effect estimation. How to block designs in an optimal way has a great importance in practice.In this study, some information are given about factorial and two-level fractional factorial designs. Concepts of resolution and minimum aberration, defining relation contrasts, block and treatment word length patterns are introduced.Existing optimality criterias for choosing blocked factorial and fractional factorial designs and minimum moment aberration which compares designs without using defining relation contrasts and word length patterns are examined.In the application of this study, designs given in the catalogue of optimal blocking schemes, provided by Sun, Wu and Chen, are examined. The best method of finding optimal blocking schemes is chosen and the reasons of choice are explained.Key Words: Factorial Desings, Fractional Factorial Designs, Word Length Patterns, Minimum Aberration, Optimal Blocking Schemes.