Practices of Color Classification

Color categories sit at the intersection of 2 central topics in the study of human cognition: (a) the analysis of vision, and (b) the study of semantic categories, or more generally processes of classification. Using as data videotape of archaeologists filling out a coding sheet that requires them to systematically describe the color of the dirt they have excavated, this article describes the practices required to competently classify color within the work life of their profession. The task of color classification is embedded within a situated activity system, which includes not only several different ways of identifying the same color (each designed for alternative uses), but also cognitive artifacts, such as a Munsell color chart and specific embodied practices. The chart creates a historically constituted architecture for perception, a heterotopia that juxtaposes in a single visual field 2 very different kinds of space. As multiple parties fill out the coding sheet together, the full resources of the organization of talk-in-interaction are brought to bear on the contingent tasks they are charged with accomplishing. This investigation of a situated activity system encompassing not only semantic categories, but also physical tools and embodied practices, contrasts with most previous research on color categories, which has focused almost exclusively on mental phenomena, and not on how people perform color classification to pursue a relevant course of action in the consequential settings that make up their lifeworld.     

Tests for equality of variances with paired data

The normal theory test for equality of variances with paired data is shown to be nonrobust to violation of the assumption of normality. Nonparametric tests are shown to provide a much safer alternative with little loss of efficiency.     

Two-sample post-stratified or subgroup analysis with restricted randomization rules

In a clinical trial to compare two treatments, subjects may be allocated sequentially to treatment groups by a restricted randomization rule. Suppose that at the end of the trial, the investigator is interested in a post-stratified or subgroup analysis with respect to a particular demographic or clinical factor which was not selected prior to the trial for stratified randomization. Under a randomization model, large sample theory of two-sample post-stratified permutational tests is developed with a broad class of restricted randomization treatment allocation rules. The test procedures proposed here are illustrated with a real-life example. The results of this example indicate that it is not always possible to ignore the treatment rule used in the trial in the design-based analysis.     

Tabu search for covering arrays using permutation vectors

A covering array  CA(N;t,k,v)$\mathsf{CA}(N;t,k,v)$ is an N×k$N\times k$ array, in which in every N×t$N\times t$ subarray, each of the v^t$v^t$ possible t  -tuples over v$v$ symbols occurs at least once. The parameter t is the strength   of the array. Covering arrays have a wide range of applications for experimental screening designs, particularly for software interaction testing. A compact representation of certain covering arrays employs “permutation vectors” to encode v^t×1$v^t\times 1$ subarrays of the covering array so that a covering perfect hash family whose entries correspond to permutation vectors yields a covering array. We introduce a method for effective search for covering arrays of this type using tabu search. Using this technique, improved covering arrays of strength 3, 4 and 5 have been found, as well as the first arrays of strength 6 and 7 found by computational search.     

Microeconomic Theory and Management Education: A Social Economics Perspective

A period of extraordinary change is pressuring schools of business to rethink their curricula and mission statements in order to adapt to new environments. The authors, both economists with many years of teaching experience, focus on the microeconomics course in the core curriculum and offer proposals which introduce alternative value bases to orient, motivate, and drive the firm in the economic environment. These include proposals from the frameworks of humanistic and social economics. This revised version was published online in August 2006 with corrections to the Cover Date.     

Repŕoduction demographique et transmission genetique dans le Nord-Est de la province de Quebec (18e–20e siecles)

Ce texte présente les principaux résultats de travaux relevant de l'histoire sociale de la population, de la démographie historique et de la génétique des populations, réalisés depuis quelques années par le Centre interuniversitaire de recherches sur les populations (SOREP). Ces travaux portent sur le Nord-Est de la province de Québec (Canada), et plus particulièrement sur la région du Saguenay. Le but de nos recherches est d'éclairer la dynamique de populations régionales, du 18e au 20e siècle, et d'en tirer des indications sur la structure et l'évolution des bassins génétiques. On s'intéresse ici à quelques gènes délétères qui sont à l'origine de maladies graves dans ces régions du Québec. L'article montre comment une démarche axée sur l'étude des faits de population peut soutenir des objectifs d'épidémiologie génétique et de prévention des maladies héréditaires en général. Il aborde aussi les problèmes éthiques et juridiques soulevés par une telle démarche, essentiellement appuyée sur l'exploitation d'un fichier de population.This paper provides an overview of the main findings relating to works carried out in the last years within SOREP (Inter-university population research center). Those works pertain to the north-east of the province of Québec (Canada), and particularly to the Saguenay region, and belong to the fields of social history of population, historical demography and population genetics. The goal of our research is to study the population dynamics at the regional level, from 18th to 20th century, in order to bring about indications on the structure and evolution of the gene pool. Our interest focuses on a few defective genes which cause very severe diseases in those northeastern regions. The paper aims to illustrating how population studies as such can help genetic epidemiology and preventive actions in general. Also adressed are ethical and legal issues raised by such an approach relying on the utilization of a population register.

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Les travaux qui ont mené à cet article ont été effectués dans le cadre de SOREP (Centre interuniversitaire de recherches sur les populations). Ils ont pu être réalisés grâce à l'assistance financière du Fonds FCAR (Québec), du Conseil de recherches en sciences humaines (Ottawa), de la Fondation de l'Université du Québec à Chicoutimi, de l'Université Laval et de l'Université McGill. Notre recherche a bénéficié de nombreux échanges avec des chercheurs comme A. Swedlund, K. Weiss, M. Skolnick, R. Ward, A. Jacquard, H. Plauchu, K. Morgan, J. Feingold. Au sein de notre centre de recherches (SOREP), nous remercions également pour leur précieuse contribution R. Roy, M. Gradie, D. Gauvreau, K. Kouladjian, M. Declos, M. Thivierge, L. Bergeron et J. Morissette. Notre gratitude va aussi aux Dr. Jean Larochelle, Jean Mathieu, Jean-Pierre Bouchard, Gervais Aubin, Francis Glorieux et André Barbeau, de même qu'à la direction de CORAMH, qui ont rendu possible l'accès aux données cliniques.     

Logspline Density Estimation under Censoring and Truncation

ABSTRACT. In this paper we consider logspline density estimation for data that may be left-truncated or right-censored. For randomly left-truncated and right-censored data the product-limit estimator is known to be a consistent estimator of the survivor function, having a faster rate of convergence than many density estimators. The product-limit estimator and B-splines are used to construct the logspline density estimate for possibly censored or truncated data. Rates of convergence are established when the log-density function is assumed to be in a Besov space. An algorithm involving a procedure similar to maximum likelihood, stepwise knot addition, and stepwise knot deletion is proposed for the estimation of the density function based upon sample data. Numerical examples are used to show the finite-sample performance of inference based on the logspline density estimation.     

Promising practices and strategies for using trauma-informed child welfare practice to improve foster care placement stability: a breakthrough series collaborative

This paper will provide information on a recent Breakthrough Series Collaborative (BSC) conducted by the National Child Traumatic Stress Network on Using Trauma-Informed Child Welfare Practice to Improve Foster Care Placement Stability. Information on this particular BSC will be provided, followed by initial findings gathered from an evaluation of the BSC and metrics gathered by each of the nine participating teams throughout the BSC process. Specific trauma-informed promising strategies adopted by teams are presented along with recommendations for next steps.     

Concept guided risk assessment: Promoting prediction and understanding

This article presents a concept-guided approach to the assessment of risk in the life situations of children alleged to be maltreatment victims. This concept-guided risk assessment is theoretically based and is the first to use a nomological hierarchy which can yield itself to systematic testing for construct validity. Data were collected on 1199 cases referred for investigations of child maltreatment. Reliability was examined by applying Cronbach's alpha coefficient to the 25 risk features and the 18 risk category constructs within the seven risk areas. Convergent validity coefficients for seven risk area constructs and eighteen risk category constructs were computed and structural validity was examined using an analysis technique adapted from the multitrait-multimethod technique of Campbell and Fiske (1959). Predictive validity was assessed using a multivariate measure assessing rated risk, seriousness, and concern. In general, the results support construct validity. Improvements are needed in assessments of child vulnerability and caregiver stress. The overall psychometric evidence, combined with the model's hierarchical and theoretical nature, suggests a promising direction for future research on understanding and preventing child maltreatment.