We use the quotient of the determinant of the variance-covariance matrix of the feasible unbiased estimates,that is ,a kind of relative efficency to compare these esti-mates. The results have instructive significance for practice.

• 我们应用这些估计的协方差阵的行列式之商，即一种相对效率比较了这些估计的优劣，所得结果对实际应用具有一定指导意义。