Statistica Sinica 5(1995), 547-558

OPTIMAL BLOCK DESIGNS WITH MINIMAL

AND NEARLY MINIMAL NUMBER OF UNITS

Aloke Dey, Kirti R. Shah^* and Ashish Das

Indian Statistical Institute and University of Waterloo^*

Abstract: The study of optimal connected block designs when the number of experimental units is minimal or nearly minimal is of fairly recent origin. In this communication, several new optimality results in different classes of connected block designs are obtained for this situation.

Key words and phrases: A-, D-, E-, MV- and ψ_f-optimality, bipartite graph, spanning tree, control-test comparison.