"Fractional Factorial Designs" are of great utility in many areas of experimentation. This book presents a systematic account of such fractional factorial designs, which provide uncorrelated estimates of relevant parameters. The book explains in detail the various methods of obtaining orthogonal fractional factorial designs of different resolutions. Extensive indexes for designs are also provided. Much of this material is available here for the first time in book form. The book will be of use to advanced level students and research workers in Statistics as well as to consulting statisticians and applied workers.