College of Science, Qiqihar University

This paper considers Wilcoxon signed rank
test based on the median ranked set sample. For any fixed set size
in the proposed sampling the asymptotic distribution-free of the
test statistic is established. Then, it is proofed analytically the
Pitman efficacy of the Wilcoxon signed rank test under the median
ranked set sampling is not only higher than that under the simple
random sampling but also superior to the sign test under the median
ranked set sampling.