Modified Wilcoxon Signed-Rank Test

• 作者: Godday Uwawunkonye Ebuh Ikewelugo Cyprian Anaene Oyeka
• 来源期刊: 统计学期刊(英文)
• 学科: 医学
• 关键词: Proposed METHOD Probabilities POSITIVE ZERO Tied NEGATIVE Frequencies
• 年，卷（期）: 2012,（2）
• 页码范围: 172-176
• 页数: 5页
• 分类号: R73

摘要

This paper briefly reviews the Wilcoxon signed rank sum test and proposes a modification. Unlike the Wilcoxon method, the proposed approach does not require that the populations being studied be continuous. Also unlike the Wilcoxon signed rank test the proposed method, does not require the absence of zero differences or tied absolute values of differences. Rather the proposed method structurally makes provisions for these possibilities. The proposed test statistic also enables the estimation of the probabilities of positive, zero or tied and negative differences within the data. This was illustrated with an example and the proposed method was generally more efficient and hence more powerful than the Wilcoxon test statistic with the power increasing as the number of tied observations or zero differences increases.