© 1979 by Biometrika Trust
Generalized N-ary balanced block designs
Department of Statistics University of Karachi
Biometrics Unit, Cornell University Ithaca, New York
The concept of N-ary balanced incomplete block designs where the incidence matrix n contains the N values 0, 1, ..., N1, is extended to generalized N-ary balanced block designs, where the incidence matrix n* contains the N values ma for a = 0, 1, ..., N1, for ma = am1(a1)m0, and for any m0 and m1 satisfying 0
m0<m1. For ternary designs, m2 = 2m1m0, and thus 0
m1<m1<m2. Definitions, parameters and necessary conditions for 2* are presented. Given a fixed number v of treatments and a fixed total number N* of experimental units, a class of N-ary balanced block designs with a different set of ma is possible. Criteria are developed to select the designs in the class with the smallest variance of a contrast. Efficiency factors and a generalization of Fisher's inequality are also presented.
Key Words: Efficiency factor Incomplete block design Optimality of design