The Wilcoxon-Mann-Whitney statistic is commonly used for a distribution-free comparison of two groups. One requirement for its use is that the sample sizes of the two groups are fixed. This is violated in some of the applications such as medical imaging studies and diagnostic marker studies; in the former, the violation occurs since the number of correctly localized abnormal images is random, w...

The historical development of the two-sample rank-sum test is explored. While most textbooks and journal articles attribute the origin of the two-sample rank-sum test to Wilcoxon (1945) and/or Mann and Whitney (1947), the test was independently developed by at least six researchers in the late 1940s and early 1950s. In addition to Wilcoxon and Mann and Whitney, Festinger (1946), Whitfield (1947...

Ridit analysis has been used by a variety of investigators (e.g., 1-5) and has appeared in a t least one textbook (6). Bross (7) introduced the technique of ridit analysis and Kantor et a1 (8) showed the relationship between the average ridit value and a quantile rank. The purpose of this article is to elaborate on the remark made by Bross (7) that "[ridit analysis is] closely related to distri...

BACKGROUND Recent findings suggest that exposure to organochlorine (OC) compounds, chlordanes and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in particular, may increase the risk of developing testicular germ cell tumors (TGCTs). OBJECTIVE To further investigate this question, we conducted a nested case-control study of TGCTs within the Norwegian Janus Serum Bank cohort. METHODS The st...

In complex survey sampling, a fraction of a finite population is sampled. Often, the survey is conducted so that each subject in the population has a different probability of being selected into the sample. Further, many complex surveys involve stratification and clustering. For generalizability of the sample to the finite population, these features of the design are usually incorporated in the...

The hypothesis that altered expression of specific coactivators/repressors of the estrogen receptor occurs during human breast tumorigenesis in vivo is examined in this study. Using in situ hybridization and reverse transcription-PCR assays, the expression of two coactivators (SRA and AIB1) and one repressor (REA) of the estrogen receptor was compared between matched breast tumors and adjacent ...

The hypothesis that altered expression of specific coactivators/repressors of the estrogen receptor occurs during human breast tumorigenesis in vivo is examined in this study. Using in situ hybridization and reverse transcription-PCR assays, the expression of two coactivators (SRA and AIB1) and one repressor (REA) of the estrogen receptor was compared between matched breast tumors and adjacent ...

The Wilcoxon rank sum test is frequently used in statistical practice for the comparison of measures of location when the underlying distributions are far from normal or not known in advance. An assumption of the ordinary rank sum test is that individual sampling units are independent. In many ophthalmologic clinical trials, the Early Treatment for Diabetic Retinopathy Scale (ETDRS) is a princi...

A large part of previous work dealt with the robustness of parametric significance tests against nonnormality, heteroscedasticity, or a combination of both. The behavior of tests under violations of the independence assumption received comparatively less attention. Therefore, in applications, researches may overlook that robustness and power properties of tests can vary with the sign and the ma...

Amaç: Antidepresanlar reseptör özelliklerine göre kardiak otonomik sinir sistemi işleyişi üzerine farklı etkiler gösterebilir. Bu nedenle farklı gruplardaki antidepresanların değişen boyutlarda kardiak değerleri etkilemesi beklenebilir. Bu çalışma bir serotonin ve noradrenalin geri alım inhibitörü olan venlafaksin ile bir seçici noradrenalin geri alım inhibitörü olan reboksetinin elektrokardiyo...