Document Type
Article
Original Publication Date
2014
Journal/Book/Conference Title
PLoS ONE
Volume
9
Issue
11
DOI of Original Publication
10.1371/journal.pone.0112924
Date of Submission
November 2015
Abstract
We propose a new nonparametric test for ordered alternative problem based on the rank difference between two observations from different groups. These groups are assumed to be independent from each other. The exact mean and variance of the test statistic under the null distribution are derived, and its asymptotic distribution is proven to be normal. Furthermore, an extensive power comparison between the new test and other commonly used tests shows that the new test is generally more powerful than others under various conditions, including the same type of distribution, and mixed distributions. A real example from an anti-hypertensive drug trial is provided to illustrate the application of the tests. The new test is therefore recommended for use in practice due to easy calculation and substantial power gain.
Rights
Copyright © 2014 Shan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Is Part Of
VCU Biostatistics Publications
Comments
Originally published at http://dx.doi.org/10.1371/journal.pone.0112924