On construction ofT m -type PBIB designs

Summary Recently Saha and Das 10] constructed partially balanced incomplete block (PBIB) designs of two and more associate classes by using confounded designs for 2 ⁿ factorials. Several new designs of two associate classes were obtained through those methods. This paper generalizes one of the earlier methods of construction to obtain several series ofT _m -type (m≧2) PBIB designs, i.e., the designs havingm-dimensional triangular association schemes. Some more new designs of two associate classes (i.e.,T ₂-type) are obtained through the generalized methods of construction.