Wilcoxon's signed‐rank statistic: what null hypothesis and why it matters

In statistical literature, the term ‘signed‐rank test’ (or ‘Wilcoxon signed‐rank test’) has been used to refer to two distinct tests: a test for symmetry of distribution and a test for the median of a symmetric distribution, sharing a common test statistic. To avoid potential ambiguity, we propose to refer to those two tests by different names, as ‘test for symmetry based on signed‐rank statistic’ and ‘test for median based on signed‐rank statistic’, respectively. The utility of such terminological differentiation should become evident through our discussion of how those tests connect and contrast with sign test and one‐sample t‐test. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

Subset selection for normal means in multi-factor experiments

The procedure of Gupta [1956], [1965] for selecting a random sized subset of k ≧ 2 normal populations which contains the population with the largest population mean when the populations have a common variance is generalized to multi-factor experiments. Two-factor experiments with equal replication on each factor-level combination are discussed in detail. The cases of zero and non-zero interactions between factor levels are considered. For the two-factor, zero interaction case with a common number of observations at each factor-level combination, a table of constants necessary to implement the procedure is provided for experiments having selected levels per factor; the constants are equi-coordinate upper percentage points of a multivariate Student t distribution.     

Bayesian inference for the variance components in general mixed linear models

The general mixed linear model, containing both the fixed and random effects, is considered. Using gamma priors for the variance components, the conditional posterior distributions of the fixed effects and the variance components, conditional on the random effects, are obtained. Using the normal approximation for the multiple t distribution, approximations are obtained for the posterior distributions of the variance components in infinite series form. The same approximation Is used to obtain closed expressions for the moments of the variance components. An example is considered to illustrate the procedure and a numerical study examines the closeness of the approximations.     

Exact Uniform Confidence Bands for Periodic Regression

Exact uniform confidence bands are presented for a sinusoidal regression model with known period. A table of probability points is presented for an important special case. A comparsion is made with the Working - Hotelling - Scheffé confidence bands.     

Homosexuality and the Military: A Review of the Literature

Homosexual men and women have been subjected to constant discrimination and stigma while trying to do what most heterosexual individuals take for granted, serving their country. It is somewhat paradoxical that gays and lesbians who are treated as second-class citizens by their own country and government, with limited rights, would want to risk their lives and potentially die for that same country. As the literature illustrates, many homosexual men and women have chosen such a profession in order to justify their existence and demonstrate that they are worthy of the same rights as others. Just as women and African Americans eventually earned their status as equal members of society and proved their worthiness to serve in the military, homosexuals are now trying to achieve the same.     

Reassessing service courses in statistics

Service courses in statistics are frequently criticized by students as being unnecessary or Irrelevant to their educational goals. This article examine the teaching of undergraduates service courses. Indentifying several areas critical to the sucess of the courses.General Philosphing conceriningthe resoultions of the problems associated with the teaching of an undergraduates service courses are proposed as well as the specific suggestionsfor a course for a social science majors     

西部大开发与我国经济可持续发展

指出充分认识我国经济必须实施可持续发展战略的重要性及我国西部大开发将对我国经济可持续发展产生的重大影响 ,提出在西部大开发中实施可持续发展的对策 :(1)人才是关键 ;(2 )科教要先行 ;(3)实现资源开发与生态保持的良性循环是前提 ;(4 )要以农业发展为基础     

Using biweight m-estimates in the two-sample problem part 1: symmetric populations

We propose replacing the usual Student's-t statistic, which tests for equality of means of two distributions and is used to construct a confidence interval for the difference, by a biweight-“t” statistic. The biweight-“t” is a ratio of the difference of the biweight estimates of location from the two samples to an estimate of the standard error of this difference. Three forms of the denominator are evaluated: weighted variance estimates using both pooled and unpooled scale estimates, and unweighted variance estimates using an unpooled scale estimate. Monte Carlo simulations reveal that resulting confidence intervals are highly efficient on moderate sample sizes, and that nominal levels are nearly attained, even when considering extreme percentage points.