Unbiased Condition of the Dispersion Effects Estimator in Unreplicated Two-Level Factorial Experiments

This article presents a general form of the estimator for identifying dispersion effects from unreplicated two-level factorial experiments,and shows that the widely used estimators such as the BH,MH,and AMH estimators are all special cases of the proposed one,designated as the G estimator.The unbiased condition of the G estimator is proved,and a lower bound of variance of the G estimator is provided.A simulation based on a realistic design illustrates the variation of the variance and MSE(mean square error) of the G estimator on different coefficients.This estimator may be more flexible and has better performance than other methods such as the BH and MH estimators by appropriately selecting the coefficients.