Second Order Slope Rotatable Designs under Intra-Class Correlated Error Structure Using Balanced Incomplete Block Designs

Abstract

In this paper, following the works of Das [9] and Das et al. [10], construction of second order slope rotatable designs (SOSRD) under intra-class correlated error structure using balanced incomplete block designs (BIBD) is suggested. We may point out here that this SOSRD under intra-class correlated error structure using BIBD with parameters (v=7, b=7, r=3, k=3, λ=1) has only 71 design points for 7 factors, where as the corresponding SOSRD under intra-class correlated error structure using central composite designs (CCD) needs 79 design points. Thus this method sometimes leads to a SOSRD under intra-class correlated error structure using BIBD in less number of design points than the corresponding SOSRD under intra-class correlated error structure using CCD.