Some Remarks on Statistical Education

A definition of the subject of statistics is given, and the difference between the chalkboard world of the teacher of statistics and the real world of the experimenter is stressed. An overemphasis on significance testing, hypothesis testing, and decision procedures has led to a de-emphasis of statistical design. The teaching of statistical design theory, statistics teaching in a changing world, the importance of model building, and different approaches to teaching statistics are discussed. Some published materials developed to meet teaching needs and a new type of statistics course are described. Information about special issues in statistical education (teaching and consulting) is presented.     

Omnibus test of normality using the Q statistic

A new statistical procedure for testing normality is proposed. The Q statistic is derived as the ratio of two linear combinations of the ordered random observations. The coefficients of the linear combinations are utilizing the expected values of the order statistics from the standard normal distribution. This test is omnibus to detect the deviations from normality that result from either skewness or kurtosis. The statistic is independent of the origin and the scale under the null hypothesis of normality, and the null distribution of Q can be very well approximated by the Cornish-Fisher expansion. The powers for various alternative distributions were compared with several other test statistics by simulations.     

Decomposition of cumulative chi-squared statistics,with some new tools for their interpretation

It is well known that the Pearson statistic \(\chi ^{2}\) can perform poorly in studying the association between ordinal categorical variables. Taguchi’s and Hirotsu’s statistics have been introduced in the literature as simple alternatives to Pearson’s chi-squared test for contingency tables with ordered categorical variables. The aim of this paper is to shed new light on these statistics, stressing their interpretations and characteristics, providing in this way new and different interpretations of these statistics. Moreover, a theoretical scheme is developed showing the links between the different proposals and classes of cumulative chi-squared statistical tests, starting from a unifying index of heterogeneity, unalikeability and variability measures. Users of statistics may find it attractive to understand well the different proposals. Some decompositions of both statistics are also highlighted. This paper presents a case study of optimizing the polysilicon deposition process in a very large-scale integrated circuit, to identify the optimal combination of factor levels. It is obtained by means of the information coming from a correspondence analysis based on Taguchi’s statistic and regression models for binary dependent variables. A new optimal combination of factor levels is obtained, different from many others proposed in the literature for this data.     

Indices of Dependence Between Types in Multivariate Point Patterns

We propose new summary statistics quantifying several forms of dependence between points of different types in a multi-type spatial point pattern. These statistics are the multivariate counterparts of the J -function for point processes of a single type, introduced by Lieshout & Baddeley (1996). They are based on comparing distances from a type i point to either the nearest type j point or to the nearest point in the pattern regardless of type to these distances seen from an arbitrary point in space. Information about the range of interaction can also be inferred. Our statistics can be computed explicitly for a range of well-known multivariate point process models. Some applications to bivariate and trivariate data sets are presented as well.     

联合均值与方差模型的统计诊断

研究了联合均值与方差模型,考虑了基于数据删除模型的参数估计和统计诊断,比较删除模型与未删除模型相应统计量之间的差异。首次提出了基于联合均值与方差模型的诊断统计量和局部影响分析。通过模拟研究和实例分析,给出了不同的诊断统计量来判别异常点或强影响点,研究表明提出的理论和方法是有用和有效的。     

Evaluation of weighted rankings using expected significance level

The use of weighted rankings to analyze complete blocks designs (Quade, 1979) is a practical way of recovering between-block information. A family of old and new test statistics can be generated by this procedure. Selection among these statistics and comparison with parametric and nonparametric competitors are based on expected significance level [ESL] in small designs (3 to 6 blocks, 3 to 5 treatments).     

Hidden Second‐order Stationary Spatial Point Processes

In the existing statistical literature, the almost default choice for inference on inhomogeneous point processes is the most well‐known model class for inhomogeneous point processes: reweighted second‐order stationary processes. In particular, the K‐function related to this type of inhomogeneity is presented as the inhomogeneous K‐function. In the present paper, we put a number of inhomogeneous model classes (including the class of reweighted second‐order stationary processes) into the common general framework of hidden second‐order stationary processes, allowing for a transfer of statistical inference procedures for second‐order stationary processes based on summary statistics to each of these model classes for inhomogeneous point processes. In particular, a general method to test the hypothesis that a given point pattern can be ascribed to a specific inhomogeneous model class is developed. Using the new theoretical framework, we reanalyse three inhomogeneous point patterns that have earlier been analysed in the statistical literature and show that the conclusions concerning an appropriate model class must be revised for some of the point patterns.     

Image search using trained flexible shape models

This paper describes a technique for building compact models of the shape and appearance of flexible objects seen in two-dimensional images. The models are derived from the statistics of sets of images of example objects with ‘landmark’ points labelled on each object. Each model consists of a flexible shape template, describing how the landmark points can vary, and a statistical model of the expected grey levels in regions around each point. Such models have proved useful in a wide variety of applications. We describe how the models can be used in local image search and give examples of their application.     

Image search using trained flexible shape models

This paper describes a technique for building compact models of the shape and appearance of flexible objects seen in two-dimensional images. The models are derived from the statistics of sets of images of example objects with 'landmark' points labelled on each object. Each model consists of a flexible shape template, describing how the landmark points can vary, and a statistical model of the expected grey levels in regions around each point. Such models have proved useful in a wide variety of applications. We describe how the models can be used in local image search and give examples of their application.     

Opportunities and challenges for industrial statisticians

The last 20 years have seen significant advances in the use of statistical methodology in industry, with applications in new product design and development, optimization and control of manufacturing processes, and in the service industries. The field of industrial statistics has emerged as an important branch of statistical science that focuses on this application environment. Yet as applications of statistics in industry have expanded, creating many new opportunities for the modern industrial statistician, many new challenges have arisen. Some of these challenges are technical, while others have managerial and organizational aspects. There are also important concerns pertaining to training and education. This presentation focuses on some of these issues, and identifies some potential solutions.     

Opportunities and challenges for industrial statisticians

The last 20 years have seen significant advances in the use of statistical methodology in industry, with applications in new product design and development, optimization and control of manufacturing processes, and in the service industries. The field of industrial statistics has emerged as an important branch of statistical science that focuses on this application environment. Yet as applications of statistics in industry have expanded, creating many new opportunities for the modern industrial statistician, many new challenges have arisen. Some of these challenges are technical, while others have managerial and organizational aspects. There are also important concerns pertaining to training and education. This presentation focuses on some of these issues, and identifies some potential solutions.     

A Third Order Point Process Characteristic

Second order characteristics, in particular Ripley's K -function, are widely used for the statistical analysis of point patterns. We examine a third order analogue, namely the mean number T ( r ) of r -close triples of points per unit area. Equivalently this is the expected number of r -close point pairs in an r -neighbourhood of the typical point. Various estimators for this function are proposed and compared, and we give an explicit formula for the isotropic edge correction. The theoretical value of T seems to be unobtainable for most point process models apart from the homogeneous Poisson process. However, simulation studies show that the function T discriminates well between different types of point processes. In particular it detects a clear difference between the Poisson process and the Baddeley–Silverman cell process whereas the K -functions for these processes coincide.     

On the analysis of mortality events associated with a prespecified fixed point

"A model-based approach to the analysis of disease incidence around a fixed point is presented by considering the radial and directional effects to be expected from emissions from a putative source. In addition we present some score statistics which can be used to test for spatial effects." The methods discussed are applied to the analysis of bronchitis mortality around a reprocessing plant in Bonnybridge, Scotland.     

统计概念解析

本文从分析统计的本质属性出发,根据统计广泛性特点,归纳广义统计和狭义统计的概念,建立“统计概念总系”,力求能够包罗统计万象,体现统计全貌,使统计这一事物有一个总纲纪,为人们全面认识统计提供了一个新的视角。文中重点对政府统计纵向构成进行了分析和解读,解开人们在传统认识上的挽扣儿,这是正确理解政府统计构成的关键认识点,由此方能建立起统计概念体系。     

统计基层基础建设评价方法的研究

 统计基层基础建设和评价方法是提高统计数据质量、提高统计能力、提高统计公信力及推进“企业一套表”实施的基础和保障。本文针对河北省统计基层基础建设和评价方法问题,首先,对统计基层基础的定义进行了阐述,分析了河北省在加强统计基层基础工作前存在的主要问题;在老虑不同地区形成的代表性差异,科学选择试点,进行深入研究的基础上,提出了县、乡两级统计基层基础建设和评价方法的具体思路和实施办法,重点对如何加强基层统计工作问题进行了研究,并通过初步实施、以点带面,促进了全省统计基层基础工作水平的全面提升,取得了显著的效果。     

Experience Simpson's Paradox in the Classroom

Simpson's paradox is a challenging topic to teach in an introductory statistics course. To motivate students to understand this paradox both intuitively and statistically, this article introduces several new ways to teach Simpson's paradox. We design a paper toss activity between instructors and students in class to engage students in the learning process. We show that Simpson's paradox widely exists in basketball statistics, and thus instructors may consider looking for Simpson's paradox in their own school basketball teams as examples to motivate students’ interest. A new probabilistic explanation of Simpson's paradox is provided, which helps foster students’ statistical understanding. Supplementary materials for this article are available online.     

General bounds and inequalities in order statistics

This article is primarily a review of recent work on inequalities requiring no or only mild ssumptions.As feature,unified approaches are given for the derivation of algebraic inequalities involving linear functions of order statistics. Various inequalities for the expected value of such functions are presented. A new result is that a class of these inequalities can be improved by use of a theorem for ordered sums. Some other recent results are noted. Applications are indicated throughout.     

Statistics and risk in the nuclear industry

Nuclear power, after a decade of being ignored, is again becoming an option—perhaps the preferred option—for future power generation in Britain. Can it be done safely? As importantly, can existing plant be decommissioned safely? Granville Tunnicliffe Wilson has worked on a series of statistical projects with the nuclear industry, stretching over a period of 30 years. He looks at the part statistics has played in past safety assurance and the questions that are now being asked about its role. He also reveals past cases where operators failed to follow valid statistical indicators of plant failure.     

Official statistics, public policy and public trust

Summary.  The question of public confidence in official statistics has been central to government statistical policy for the last 10 years. This year the Statistics and Registration Service Act 2007 was passed. The paper suggests key characteristics of the new arrangements that will be needed if public confidence in the official statistics outputs is to be strengthened. It is argued that this will depend on public confidence in the statistical system as a whole rather than just the new Board. The organizational structure of the UK statistical system is described and this is linked to the issue of public confidence. Finally the wider questions of evidence-based policy and the use of statistics and statistical thinking throughout government are discussed.