Comparing diagnostic tests: test of hypothesis for likelihood ratios

Likelihood ratios (LRs) are used to characterize the efficiency of diagnostic tests. In this paper, we use the classical weighted least squares (CWLS) test procedure, which was originally used for testing the homogeneity of relative risks, for comparing the LRs of two or more binary diagnostic tests. We compare the performance of this method with the relative diagnostic likelihood ratio (rDLR) method and the diagnostic likelihood ratio regression (DLRReg) approach in terms of size and power, and we observe that the performances of CWLS and rDLR are the same when used to compare two diagnostic tests, while DLRReg method has higher type I error rates and powers. We also examine the performances of the CWLS and DLRReg methods for comparing three diagnostic tests in various sample size and prevalence combinations. On the basis of Monte Carlo simulations, we conclude that all of the tests are generally conservative and have low power, especially in settings of small sample size and low prevalence.     

中美大学生权力距离对比研究

在跨文化研究理论中，Hofstede提出的民族文化五维度是被广为接受的研究成果。根据权力距离维度理论，权力距离可以用权力距离指数来显示，他认为中国的权力距离指数高于美国。随着中国经济环境的变化和对外开放进程的加快，文化也会不断发展和变化。因此，在新的环境下研究中美权力距离差异具有现实意义。为了对比当下中美大学生的权力距离感知，在中美两所大学发放调查问卷，分别考察了两组学生对于教师、长者和家长所拥有权力的态度，并用SPSS对调查数据进行分析。结果发现，对于教师和长者，中国学生的权力距离显著高于美国学生，但是对于家长，两国学生并未表现出明显差异，这与Hofstede的研究结果不符。     

A Five-Decision Testing Procedure to Infer the Value of a Unidimensional Parameter

ABSTRACT

A statistical test can be seen as a procedure to produce a decision based on observed data, where some decisions consist of rejecting a hypothesis (yielding a significant result) and some do not, and where one controls the probability to make a wrong rejection at some prespecified significance level. Whereas traditional hypothesis testing involves only two possible decisions (to reject or not a null hypothesis), Kaiser’s directional two-sided test as well as the more recently introduced testing procedure of Jones and Tukey, each equivalent to running two one-sided tests, involve three possible decisions to infer the value of a unidimensional parameter. The latter procedure assumes that a point null hypothesis is impossible (e.g., that two treatments cannot have exactly the same effect), allowing a gain of statistical power. There are, however, situations where a point hypothesis is indeed plausible, for example, when considering hypotheses derived from Einstein’s theories. In this article, we introduce a five-decision rule testing procedure, equivalent to running a traditional two-sided test in addition to two one-sided tests, which combines the advantages of the testing procedures of Kaiser (no assumption on a point hypothesis being impossible) and Jones and Tukey (higher power), allowing for a nonnegligible (typically 20%) reduction of the sample size needed to reach a given statistical power to get a significant result, compared to the traditional approach.     

The Poisson-X family of distributions

ABSTRACT

Recently, Risti? and Nadarajah [A new lifetime distribution. J Stat Comput Simul. 2014;84:135–150] introduced the Poisson generated family of distributions and investigated the properties of a special case named the exponentiated-exponential Poisson distribution. In this paper, we study general mathematical properties of the Poisson-X family in the context of the T-X family of distributions pioneered by Alzaatreh et al. [A new method for generating families of continuous distributions. Metron. 2013;71:63–79], which include quantile, shapes of the density and hazard rate functions, asymptotics and Shannon entropy. We obtain a useful linear representation of the family density and explicit expressions for the ordinary and incomplete moments, mean deviations and generating function. One special lifetime model called the Poisson power-Cauchy is defined and some of its properties are investigated. This model can have flexible hazard rate shapes such as increasing, decreasing, bathtub and upside-down bathtub. The method of maximum likelihood is used to estimate the model parameters. We illustrate the flexibility of the new distribution by means of three applications to real life data sets.     

道德困境折射出的权力关系——评亨利·詹姆斯的《螺丝在拧紧》

文章从维多利亚时期以男性为主体的社会现实为切入点,分析了处于社会底层的女教师受到的来自男权社会及其代表者布莱庄园男主人的控制与压迫,以及她对于这种控制的反抗,并借助符号矩阵来进一步展示存在于控制与反抗的道德困境中的权力关系。     

村民自治背景下的村级公共权力厘定

村民自治背景下,基层社会治理发生了重大转变,以村级公共权力为视角进行观察,能够比较准确地反映这种转变。基于对制度文本及实践模式的研究,村级公共权力的基本内涵可以确定为,在中国共产党领导下的村级政治主体为实现村级公共利益进行民主选举、民主决策、民主管理、民主监督的法定权力。在这一基本内涵的基础上可以发现,村级公共权力的静态回路是一个多主体多层次的复杂体系,且其运行过程存在不同环节的发展不均衡和结果低效率的现象。     

Community Resilience and Decision Theory Challenges for Catastrophic Events

Extreme and catastrophic events pose challenges for normative models of risk management decision making. They invite development of new methods and principles to complement existing normative decision and risk analysis. Because such events are rare, it is difficult to learn about them from experience. They can prompt both too little concern before the fact, and too much after. Emotionally charged and vivid outcomes promote probability neglect and distort risk perceptions. Aversion to acting on uncertain probabilities saps precautionary action; moral hazard distorts incentives to take care; imperfect learning and social adaptation (e.g., herd‐following, group‐think) complicate forecasting and coordination of individual behaviors and undermine prediction, preparation, and insurance of catastrophic events. Such difficulties raise substantial challenges for normative decision theories prescribing how catastrophe risks should be managed. This article summarizes challenges for catastrophic hazards with uncertain or unpredictable frequencies and severities, hard‐to‐envision and incompletely described decision alternatives and consequences, and individual responses that influence each other. Conceptual models and examples clarify where and why new methods are needed to complement traditional normative decision theories for individuals and groups. For example, prospective and retrospective preferences for risk management alternatives may conflict; procedures for combining individual beliefs or preferences can produce collective decisions that no one favors; and individual choices or behaviors in preparing for possible disasters may have no equilibrium. Recent ideas for building “disaster‐resilient” communities can complement traditional normative decision theories, helping to meet the practical need for better ways to manage risks of extreme and catastrophic events.     

Monte Carlo comparison of five exponentiality tests using different entropy estimates

The paper studies five entropy tests of exponentiality using five statistics based on different entropy estimates. Critical values for various sample sizes determined by means of Monte Carlo simulations are presented for each of the test statistics. By simulation, we compare the power of these five tests for various alternatives and sample sizes.     

论近代中国士人的首次西游书写

斌椿的日记《乘槎笔记》和诗集《海国胜游草》、《天外归帆草》突破了近代史书写的一贯"以西律中"的现代化话语模式。这一方面可以从满族/中国这一本土坐标看待近代中西交流史的这桩公案;另一方面也可以反思体用二元割裂的思考方式。     

Strangers within? Russian-speakers’ migration from Latvia to London: a study in power geometry and intersectionality

ABSTRACT

This paper seeks to contribute to debates on ethnic identification and migration through a focus on a specific group – Russian-speakers from the Baltic state of Latvia who have migrated to the UK. Twenty-six interviews with members of this group were gathered in London and the wider metropolitan area during 2012 and 2014. Russian-speakers represent uniquely combined configurations of ‘the other within’: in most cases, they are EU citizens with full rights; yet, some still hold non-citizens’ passports of Latvia. While in Latvian politics Russian-speakers are framed as ‘others’ whose identities are shaped by the influence of Russia, interview findings confirm that they do not display belonging to contemporary Russia. However, London is the ‘third space’ – a multicultural European metropolis – which provides new opportunities for negotiating ethnic identification. Against the background of triple ‘alienation’ (from Latvia, from Russia and from the UK), we analyse how ethnicity is narrated intersectionally with other categories such as age and class. The findings show that Russian-speaking migrants from Latvia mobilise their Europeanness and Russianness beyond alienating notions of (ethno)national identity. The paper also demonstrates that being open to ethnicity as a category of practice helps us towards a progressive conceptualisation of often overlooked dimensions of integration of intra-EU linguistic ‘others’.