International Journal of Mathematics and Mathematical Sciences
Volume 3 (1980), Issue 1, Pages 169-175

On the block structure of PBIB designs

M. L. Chandak

Department of Mathematics and Statistics, J.N. Agricultural University, Jabalpur–4, M.P., India

Received 11 August 1978; Revised 2 February 1979

Copyright © 1980 M. L. Chandak. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Let {θ,θ1,,θn1} denote the set having any treatment θ and its n1 first associates in a PBIB design with m(2) associate classes. A theorem on distribution of the elements of this set among the blocks of the block design is proved and results related to certain well known association schemes of three associate classes are obtained.