The sample monomode and an associated test for discrete monomodality

Abstract

The notions of (sample) mean, median and mode are common tools for describing the central tendency of a given probability distribution. In this article, we propose a new measure of central tendency, the sample monomode, which is related to the notion of sample mode. We also illustrate the computation of the sample monomode and propose a statistical test for discrete monomodality based on the likelihood ratio statistic.     

Age-period-cohort analysis: an illustration of the problems in assessing interaction in one observation per cell data

This paper discusses the specific problems of age-period-cohort (A-P-C) analysis within the general framework of interaction assessment for two-way cross-classified data with one observation per cell. The A-P-C multiple classification model containing the effects of age groups (rows), periods of observation (columns), and birth cohorts (diagonals of the two-way table) is characterized as one of a special class of models involving interaction terms assumed to have very specific forms. The so-called A-P-C identification problem, which results from the use of a particular interaction structure for detecting cohort effects, is shown to manifest itself in the form of an exact linear dependency among the columns of the design matrix. The precise relationship holding among these columns is derived, as is an explicit formula for the bias in the parameter estimates resulting from an incorrect specification of an assumed restriction on the parameters required to solve the normal equations. Current methods for modeling A-P-C data are critically reviewed, an illustrative numerical example is presented, and one potentially promising analysis strategy is discussed. However, gien the large number of possible sources for error in A-P-C analyses, it is strongly recommended that the results of such analyses be interpreted with a great deal of caution.     

On the use of MCMC computerized adaptive testing with empirical prior information to improve efficiency

The paper deals with the introduction of empirical prior information in the estimation of candidate’s ability within computerized adaptive testing (CAT). CAT is generally applied to improve efficiency of test administration. In this paper, it is shown how the inclusion of background variables both in the initialization and the ability estimation is able to improve the accuracy of ability estimates. In particular, a Gibbs sampler scheme is proposed in the phases of interim and final ability estimation. By using both simulated and real data, it is proved that the method produces more accurate ability estimates, especially for short tests and when reproducing boundary abilities. This implies that operational problems of CAT related to weak measurement precision under particular conditions, can be reduced as well. In the empirical examples, the methods were applied to CAT for intelligence testing in the area of personnel selection and to educational measurement. Other promising applications would be in the medical world, where testing efficiency is of paramount importance as well.     

A Review of Laura S. Young's Bookbinding & Conservation by Hand: A Working Guide

Abstract

University librarians in China face many of the same challenges related to serials management that confront librarians in the United States. The authors discuss the importance for librarians in the United States, especially those working with serials, to establish and build ties with librarians in other countries, such as China. Benefits of an exchange could include sharing information about best practices, exchange of serial materials, and working together on mutually advantageous projects. Acknowledging the growing interest in international library exchange programs, the authors relate their own institution's efforts to build international ties with Fudan University in Shanghai, China, and Shaanxi Normal University in Xi'an, China. In establishing these ties, the authors have traveled to China and interviewed librarians about serials acquisition, processing, and management.     

Resilience in Arts and Cultural Nonprofit Organizations: An Analysis of the Covid-19 Crisis in France

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This article seeks to analyze the resilience of arts and cultural nonprofit organizations in France during the Covid-19...     

Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book

Six multi‐decade‐long members of SRA reflect on the 1983 Red Book in order to examine the evolving relationship between risk assessment and risk management; the diffusion of risk assessment practice to risk areas such as homeland security and transportation; the quality of chemical risk databases; challenges from other groups to elements at the core of risk assessment practice; and our collective efforts to communicate risk assessment to a diverse set of critical groups that do not understand risk, risk assessment, or many other risk‐related issues. The authors reflect on the 10 recommendations in the Red Book and present several pressing challenges for risk assessment practitioners.     

On the asymptotic behaviour of the recursive Nadaraya–Watson estimator associated with the recursive sliced inverse regression method

We investigate the asymptotic behaviour of the recursive Nadaraya–Watson estimator for the estimation of the regression function in a semiparametric regression model. On the one hand, we make use of the recursive version of the sliced inverse regression method for the estimation of the unknown parameter of the model. On the other hand, we implement a recursive Nadaraya–Watson procedure for the estimation of the regression function which takes into account the previous estimation of the parameter of the semiparametric regression model. We establish the almost sure convergence as well as the asymptotic normality for our Nadaraya–Watson estimate. We also illustrate our semiparametric estimation procedure on simulated data.     

Equity,inclusion, and antiblackness in mathematics education

ABSTRACT

Despite decades of equity- and inclusion-oriented discourse and reform in mathematics education, Black learners in the U.S. continue to experience dehumanizing and violent forms of mathematics education. I suggest that equity for Black learners in mathematics education is a delusion rooted in the fictions of white imaginaries, contingent on appeasing white logics and sensitivities, and characterized at best by incremental changes that do little to threaten the maintenance of racial hierarchies inside or outside of mathematics education. Moreover, the forms of inclusion offered up in equity-oriented discourses and reforms represent contexts of containment and enclosure that keep Black people in their same relative position. Refusal is suggested as a strategy for Black learners to resist the anti-Black character of mathematics education, and as a first step in actualizing forms of mathematics education that are worthy of Black learners.     

Estimation of seroprevalence, rape, and homelessness in the United States using a social network approach

The authors have developed and tested scale-up methods, based on a simple social network theory, to estimate the size of hard-to-count subpopulations. The authors asked a nationally representative sample of respondents how many people they knew in a list of 32 subpopulations, including 29 subpopulations of known size and 3 of unknown size. Using these responses, the authors produced an effectively unbiased maximum likelihood estimate of the number of people each respondent knows. These estimates were then used to back-estimate the size of the three populations of unknown size. Maximum likelihood values and 95% confidence intervals are found for seroprevalence, 800,000 +/- 43,000; for homeless, 526,000 +/- 35,000; and for women raped in the last 12 months, 194,000 +/- 21,000. The estimate for seroprevalence agrees strikingly with medical estimates, the homeless estimate is well within the published estimates, and the authors' estimate lies in the middle of the published range for rape victims.     

State versus Market: Contending Interests in the Struggle to Control French Accounting Standardisation

The paper concerns the struggle between different interest groups to control or significantly influence the objectives, institutional arrangements and processes of French accounting standardisation. Its particular focus of interest is the state agency established to deal with standardisation, namely the National Accounting Council, the Conseil National de la Comptabilité (CNC), and its predecessors. The period addressed spans from 1941 to the present, marked by the first attempt to implement a national accounting code, adoption of the initial post-war code in 1947 and subsequent revisions.The paper identifies and examines the role played by the French state in establishing an institutional structure for accounting standardisation and in seeking to influence operation of that structure as a means to achieve a concertation of diverse social and economic interest groups with an interest in accounting standards. The objective for the process from the viewpoint of the state has been seen as the intended dominance of certain interests of state over other interests, whether public sector or otherwise. In the course of time, the dominant interests of the state have changed in the face of changing expectations about the role of financial accounting and reporting in the financial life of France. The role of the state is seen to have come under increasing pressure from private sector interests in France and externally. Particular attention is given to the 1996–8 major reforms to the CNC and associated new regulatory structure.The possibility is assessed of whether and under what terms the French approach to accounting standardisation can be sustained, grounded as it is in a profound attachment by the state to the values of the Etat colbertiste.