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1.
李群 《统计教育》2003,(6):10-12
加入WTO后我国统计调查面临新的机遇和挑战。近年,统计调查的无限制在一些地方成了一种公害,其中各地政府部门统计也出现了“多、乱、陋、杂”现象,规范统计调查势在必行。规范统计调查,就是要完善统计系统,提高透明度,加速与国际经济制度接轨,在宏观经济统计上实行国际通行的标准。  相似文献   

2.
Each semester approximately 80% of the students taught by the Florida State University Department of Statistics are enrolled in STA 3014: Fundamental Business Statistics. During the academic year this course is taught in large lecture sections of 250 students each. It is either the only statistics course or one of two statistics courses taken in their undergraduate career for probably 90% of these students. A similar situation exists in many statistics departments around the nation.

These large introductory courses offer us the opportunity to introduce the power of statistics to a large fraction of our future business leaders. In the past it appears that this opportunity has often been missed. In fact, some suggest that these courses help contribute to the general public's negative attitude toward statistics courses, the discipline of statistics, and statisticians.

Hence, I propose that one of the current challenges in statistics is the challenge of improving the quality of these courses so that statistics may contribute to the improvement of quality and productivity in the United States, a vital national issue. In this paper I report on my experiences in grappling with this challenge in STA 3014.  相似文献   

3.
ABSTRACT

In this article I will review six textbooks commonly set in University undergraduate nonparametric statistics courses. The books will be evaluated in terms of how key statistical concepts are presented; use of software; exercises; and location on a theory-applications axis and an algorithms-principles axis. The placement of books on these axes provides a novel guide for instructors looking for the book that best fits their approach to teaching nonparametric statistics.  相似文献   

4.
A Cramér-von Mises type statistic for testing bivariate independence, proposed by Hoeffding (1948) and by Blum, Kiefer, and Rosenblatt (1961), is examined in greater detail. The statistic is decomposed into components in the manner of Durbin and Knott (1972), and the components are shown to be related to linear rank statistics. Asymptotic power properties of the Hoeffding statistic and its components in testing for independence with bivariate normal random observations are described; a Monte Carlo study comparing these statistics with other nonparametric statistics for bivariate independence is also reported.  相似文献   

5.
Two first-order uniform asymptotic linearity theorems for signed-rank statistics are given which generalize similar theorems of Jure?ková [Sankhyā Ser. A, 33, 1-18 (1971)], van Eeden [Ann. Math. Statist., 43, 791-802 (1972)], and Kraft and van Eeden [Ann. Math. Statist., 43, 42-57 (1972)]. It is seen that the concordance conditions imposed by these authors are not needed.  相似文献   

6.
目前,物流业的基本统计数据和指标是一片黑大陆,统计体系里缺乏物流资产和物流负债的相关指标。基于资产负债表构建的物流卫星账户可以测度物流业资产和负债的总量及结构。其关键在于确定物流相关产业部门。编制非金融企业资产负债表,并在其基础上剥离出和物流业相关的交通运输、仓储、邮政业和贸易业的资产负债数据。利用物流业调整系数对相关产业部门的资产和负债数据进行调整,从而编制了2003-2012年中国物流业资产负债表。以物流资产和负债为主要内容的物流卫星账户将有助于探清物流业的家底,增强物流业与其他国民经济产业部门的可比性。  相似文献   

7.
We propose to discuss at length several examples from standard text books. All of these examples deal with analysis of covariance (ANCOVA) models and related analyses of data. We intend to capitalize on our understanding of optimal covariate designs (OCDs) in different ANCOVA models and re-visit these examples with a view to suggest optimal/nearly optimal designs for estimation of the covariate parameter(s). As we will see, for some examples our task is very much routine but for others, it is indeed a highly non trivial exercise.

?We intent to cover a total of six examples—divided in two parts. This is Part I—dealing with two examples.  相似文献   

8.
A modification of Schucany's (1972) method for generating order statistics is given which allows for efficient generation of certain subsets of order statistics.  相似文献   

9.
ABSTRACT

Background: Instrumental variables (IVs) have become much easier to find in the “Big data era” which has increased the number of applications of the Two-Stage Least Squares model (TSLS). With the increased availability of IVs, the possibility that these IVs are weak has increased. Prior work has suggested a ‘rule of thumb’ that IVs with a first stage F statistic at least ten will avoid a relative bias in point estimates greater than 10%. We investigated whether or not this threshold was also an efficient guarantee of low false rejection rates of the null hypothesis test in TSLS applications with many IVs.

Objective: To test how the ‘rule of thumb’ for weak instruments performs in predicting low false rejection rates in the TSLS model when the number of IVs is large.

Method: We used a Monte Carlo approach to create 28 original data sets for different models with the number of IVs varying from 3 to 30. For each model, we generated 2000 observations for each iteration and conducted 50,000 iterations to reach convergence in rejection rates. The point estimate was set to 0, and probabilities of rejecting this hypothesis were recorded for each model as a measurement of false rejection rate. The relationship between the endogenous variable and IVs was carefully adjusted to let the F statistics for the first stage model equal ten, thus simulating the ‘rule of thumb.’

Results: We found that the false rejection rates (type I errors) increased when the number of IVs in the TSLS model increased while holding the F statistics for the first stage model equal to 10. The false rejection rate exceeds 10% when TLSL has 24 IVs and exceed 15% when TLSL has 30 IVs.

Conclusion: When more instrumental variables were applied in the model, the ‘rule of thumb’ was no longer an efficient guarantee for good performance in hypothesis testing. A more restricted margin for F statistics is recommended to replace the ‘rule of thumb,’ especially when the number of instrumental variables is large.  相似文献   

10.
ABSTRACT

Longstanding concerns with the role and interpretation of p-values in statistical practice prompted the American Statistical Association (ASA) to make a statement on p-values. The ASA statement spurred a flurry of responses and discussions by statisticians, with many wondering about the steps necessary to expand the adoption of these principles. Introductory statistics classrooms are key locations to introduce and emphasize the nuance related to p-values; in part because they engrain appropriate analysis choices at the earliest stages of statistics education, and also because they reach the broadest group of students. We propose a framework for statistics departments to conduct a content audit for p-value principles in their introductory curriculum. We then discuss the process and results from applying this course audit framework within our own statistics department. We also recommend meeting with client departments as a complement to the course audit. Discussions about analyses and practices common to particular fields can help to evaluate if our service courses are meeting the needs of client departments and to identify what is needed in our introductory courses to combat the misunderstanding and future misuse of p-values.  相似文献   

11.
Summary.  Traditionally, the use of Bayes factors has required the specification of proper prior distributions on model parameters that are implicit to both null and alternative hypotheses. I describe an approach to defining Bayes factors based on modelling test statistics. Because the distributions of test statistics do not depend on unknown model parameters, this approach eliminates much of the subjectivity that is normally associated with the definition of Bayes factors. For standard test statistics, including the χ 2-, F -, t - and z -statistics, the values of Bayes factors that result from this approach have simple, closed form expressions.  相似文献   

12.
Abstract

By using the idea of principal component analysis, we propose an approach to applying the classical skewness and kurtosis statistics for detecting univariate normality to testing high-dimensional normality. High-dimensional sample data are projected to the principal component directions on which the classical skewness and kurtosis statistics can be constructed. The theory of spherical distributions is employed to derive the null distributions of the combined statistics constructed from the principal component directions. A Monte Carlo study is carried out to demonstrate the performance of the statistics on controlling type I error rates and a simple power comparison with some existing statistics. The effectiveness of the proposed statistics is illustrated by two real-data examples.  相似文献   

13.
ABSTRACT

This paper discusses the problem of testing the complete independence of random variables when the dimension of observations can be much larger than the sample size. It is reported that two typical tests based on, respectively, the biggest off-diagonal entry and the largest eigenvalue of the sample correlation matrix lose their control of type I error in such high-dimensional scenarios, and exhibit distinct behaviours in type II error under different types of alternative hypothesis. Given these facts, we propose a permutation test procedure by synthesizing these two extreme statistics. Simulation results show that for finite dimension and sample size the proposed test outperforms the existing methods in various cases.  相似文献   

14.
The parametric bootstrap tests and the asymptotic or approximate tests for detecting difference of two Poisson means are compared. The test statistics used are the Wald statistics with and without log-transformation, the Cox F statistic and the likelihood ratio statistic. It is found that the type I error rate of an asymptotic/approximate test may deviate too much from the nominal significance level α under some situations. It is recommended that we should use the parametric bootstrap tests, under which the four test statistics are similarly powerful and their type I error rates are all close to α. We apply the tests to breast cancer data and injurious motor vehicle crash data.  相似文献   

15.
ABSTRACT

A hybrid censoring is a mixture of Type I and Type II censoring where the experiment terminates when either rth failure or predetermined censoring time comes first or later. In this article, we consider order statistics of the Type I censored data and provide a simple expression for their Kullback–Leibler (KL) information. Then, we provide the expressions for the KL information of the Type I and Type II hybrid censored data.  相似文献   

16.
A completely nonparametric approach to population bioequivalence in crossover trials has been suggested by Munk and Czado (1999). It is based on the Mallows (1972) metric as a nonparametric distance measure which allows the comparison between the entire distribution functions of test and reference formulations. It was shown that a separation between carry-over and period effects is not possible in the nonparametric setting. However when carry-over effects can be excluded, treatment effects can be assessed when period effects are or not. Munk and Czado (1999) proved bootstrap limit laws of the corresponding test statistics because estimation of the limiting variance of the test statistic is very cumbersome. The purpose of this paper is to investigate the small sample behavior of various bootstrap methods and to compare it with the asymptotic test obtained by estimation of the limiting variance. The percentile (PC) and bias correct- ed and accelerated (BCA) bootstrap were compared for multivariate normal and nonnormal populations. From the simulation results presented, the BCA bootstrap is found to be less conservative and provides higher power compared to the PC bootstrap, especially when skewed multivariate populations are present.  相似文献   

17.
Bob Boissy 《Serials Review》2013,39(4):266-267
Abstract

The Essential Electronic Agricultural Library (TEEAL) and Access to Global Online Research in Agriculture (AGORA) are programs that will provide low-income countries with access to agricultural journal literature that advances their agricultural research and education objectives. Developed by Cornell University’s Mann Library and launched in 1999, TEEAL is a self-contained agricultural research library with full-text articles and graphics of 140 major journals related to agriculture from 1993 through 2003, stored and indexed on over 400 CD-ROMs. In mid-2005, most of the collection also became available for use over local area networks. Launched in October 2003, AGORA is an Internet-based journal delivery system led by the UN Food and Agriculture Organization (FAO), with Mann Library as a principal partner. AGORA offers almost 800 journals from twenty-seven international publishers to 113 low-income countries and territories for free or a nominal fee.  相似文献   

18.
This department includes the two sections New Developments in Statistical Computing and Statistical Computing Software Reviews; suitable contents for each of these sections is described under the respective section heading. Articles submitted for the department, outside the two sections, should not be highly technical and should be relevant to the teaching or practice of statistical computing.

This section is similar in organization to a Book Review section in other journals; however, software of interest to statisticians is the subject of review here. Emphasis is on software for microcomputers. Programs that operate only in larger mainframe computers will seldom receive review. Normally, producers of programs make a copy of their product available to the Section Editor, who then selects one or more persons to test the product and prepare a review.

Producers of computer software who wish to have their product reviewed are invited to contact the Section Editor, Professor Kenneth Berk, Department of Mathematics, 313 Stevenson Hall, Illinois State University, Normal, IL 61761.

Findings and opinions expressed in every review are solely those of the author. They should not be construed as reflecting endorsement of the product, or opinions held, by the American Statistical Association, nor is any warranty implied about any product reviewed.

SYSTAT Leland Wilkinson. Available from Systat, Inc., 603 Main St., Evanston, IL 60202. $495 (multiple copy and site fees available). Reviewed by Mark I. Scherwish

AIDA, Version 9/82 David A. Lingwood, Available from Action-Research Northwest, 11442 Marine View Drive, S.W., Seattle, WA 98146. $235. Reviewed by Walter Liggett

MSUSTAT, MS/PC-DOS and CP/M-80 Version 2.20 Richard E. Lund. Available from Research and Development, Inc., Montana State University, Bozeman, MT 59717–0002. $187.50 (university and multiple-copy discounts available). Reviewed by Mervyn G. Marasinghe  相似文献   

19.
Hotelling's T 2 test is known to be optimal under multivariate normality and is reasonably validity-robust when the assumption fails. However, some recently introduced robust test procedures have superior power properties and reasonable type I error control with non-normal populations. These, including the tests due to Tiku & Singh (1982), Tiku & Balakrishnan (1988) and Mudholkar & Srivastava (1999b, c), are asymptotically valid but are useful with moderate size samples only if the population dimension is small. A class of B-optimal modifications of the stepwise alternatives to Hotellings T 2 introduced by Mudholkar & Subbaiah (1980) are simple to implement and essentially equivalent to the T 2 test even with small samples. In this paper we construct and study the robust versions of these modified stepwise tests using trimmed means instead of sample means. We use the robust one- and two-sample trimmed- t procedures as in Mudholkar et al. (1991) and propose statistics based on combining them. The results of an extensive Monte Carlo experiment show that the robust alternatives provide excellent type I error control and a substantial gain in power.  相似文献   

20.
万寿桥  徐健 《统计研究》2001,18(8):49-51
一、对企业统计和企业统计改革的反思  近年来 ,为了满足企业对市场信息的需求 ,学术界及统计工作人员对企业统计的改革提出了很多建设性意见 ,其共同点都是在维护企业统计的前提下 ,对企业统计提出了越来越高的要求。但笔者认为 ,目前企业统计人员面临的局面越来越尴尬 ,企业统计有不断削弱的趋势。因此 ,不能不对企业统计和企业统计改革有关问题提出反思。(一 )企业统计不应该是行政记录统计的原始定义应该是社会经济总体现象数量方面的调查研究活动。西方发达国家在市场经济条件下形成的关于统计的概念与我国长期以来在高度集中的计划…  相似文献   

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