FRACTIONAL 3m FACTORIAL DESIGNS WITH SPECIAL REFERENCE TO 18-RUN ORTHOGONAL 34 FACTORIAL DESIGNS

Loading vectors and loading coefficients of the parameters of a 3m factorial design and the characteristic vector of its information matrix are introduced. Specific properties of an orthogonal design derived from three-symbol orthogonal array of strength two are discussed. Orthogonal 18-run 34 factorial designs obtained respectively from the representatives of twelve isomorphic classes are reviewed and two designs among them are recommended for use from the practical point of view.