Changes in the social definition of early childhood and the new forms of symbolic violence

Conclusion The nursery school may be considered an institution and a market where the habits produced by the family are moulded, developed and standardized; thus, it is confronted with an objective definition of early childhood embedded in pedagogical practices. The proper objective of a sociology of nursery-school practice is the analysis of the lag between the functions delegated to the school by the different social classes and the functions which it objectively tends to fulfill. Here we have the best test of the lag between the pedagogic demands of the different classes and what the schools supply-which is very abstract, with results that are only visible at a later stage in the school career. It is not so much a question of learning to read or of preparing to do so (the acquisition of certain logical operations or a developed sensitivity, of acquiring a few I.Q. points). This learning takes place through many varied activities which apppear to be far from the learning function.All told, the conditions for understanding nursery-school exercises flow from the conditions for inventing these exercises. For instance, in games of manipulation, construction, classifying various objects, is not some knowledge of Piaget (at least in the sense of some psychologikal knowledge) needed to understand that practical manipulation is also logical manipulation, to see in cube games the learning of logic? Similarly, the language naïveté cultivated in language games is a clever naïveté, which supposes for example a cultured re-discovery of popular archaic language or of child talk. p ]Is it not likely to appear as pure childishness to those who, without the ncessary cultural knowledge, do not have the keys to decipher these ostensibly naïve exercises? Similarly, the conditions for understanding children's drawings as artistic learning (and the nursery school as an educational institution) are the very conditions for understanding modern art as art.It is not just a matter of perception and understanding; as the objective definition of early childhood proper to the different social classes becomes pervasive both in the relationship with school and in the socialization practices of the family, it patterns the children's habitus (as long-lasting internalized dispositions), which in turn influence the child's behavior and attitude towards school.The perception categories and the different forms of treatment of young children appropriate to each social class are not simply the result of the diffusion of definitions of early childhood produced by the autonomous evolution of scientific and artistic disciplines. They are the products of all the social and cultural conditions which define the class situation. We may also wonder whether at least some pedagogy and certain types of exercises do not presume that the child has socially marked attitudes, produced in some classes by family inculcation. For instance, a general attitude of disinterested interest is required by a pedagogy offering multiple activities and open to an attitude of active research and exploration. Does not this attitude suppose as an existential possibility the condition of social classes protected from economic pressure and from the urgency of immediate life, a general attitude towards life nearer to leisure than to the constraints of work?Thus, in confronting supply with demand—here even less than elsewhere-there is no question of comparing the expectations arising from users' opinions with the program offered in the official definition of the institution. The expectations are those which arise from objective determinations inherent in each social group, the forms of treatment and perception of early childhood. To analyze the program-and therefore to ascertain the social conditions governing the use of the nursery school—the dominant definition of early childhood on which the institution is founded must be brought to light. Moreover, the way in which this definition is written into the curriculum (and, subsequently, into pedagogical practice) must also be studied. This implies that the preliminary condition for a sociological analysis of the functions performed by the nursery school for the different social classes would be an analysis of a) the components of this dominant definition of early childhood and b) of the social conditions in those groups which make it possible to identify these components.We wish to thank P. Bourdieu for his advice during our research. R. Collins provided useful suggestions after reading the first version of this paper.     

Understanding changes in Māori incomes and income inequality 1997–2003

This paper examines recent changes in weekly income levels and dispersion for Māori, New Zealand’s indigenous ethnic group. Changes in the Māori income distribution between 1997 and 2003 reflect rapid increases in economic growth and employment rate. A reduced proportion of people had zero or benefit-level incomes and a higher proportion had high incomes. Income inequality declined for working-aged Māori and was stable for employed Māori. The average income gap between Māori and Europeans declined. The increased Māori employment rate during this period was the single most important driver of changes in the Māori income distribution.

On the minimum expected quantity for the validity of the chi-squared test in 2 2 2 tables

A 2 2 2 contingency table can often be analysed in an exact fashion by using Fisher's exact test and in an approximate fashion by using the chi-squared test with Yates' continuity correction, and it is traditionally held that the approximation is valid when the minimum expected quantity E is E S 5. Unfortunately, little research has been carried out into this belief, other than that it is necessary to establish a bound E>E*, that the condition E S 5 may not be the most appropriate (Martín Andrés et al., 1992) and that E* is not a constant, but usually increasing with the growth of the sample size (Martín Andrés & Herranz Tejedor, 1997). In this paper, the authors conduct a theoretical experimental study from which they ascertain that E* value (which is very variable and frequently quite a lot greater than 5) is strongly related to the magnitude of the skewness of the underlying hypergeometric distribution, and that bounding the skewness is equivalent to bounding E (which is the best control procedure). The study enables estimating the expression for the above-mentioned E* (which in turn depends on the number of tails in the test, the alpha error used, the total sample size, and the minimum marginal imbalance) to be estimated. Also the authors show that E* increases generally with the sample size and with the marginal imbalance, although it does reach a maximum. Some general and very conservative validity conditions are E S 35.53 (one-tailed test) and E S 7.45 (two-tailed test) for alpha nominal errors in 1% h f h 10%. The traditional condition E S 5 is only valid when the samples are small and one of the marginals is very balanced; alternatively, the condition E S 5.5 is valid for small samples or a very balanced marginal. Finally, it is proved that the chi-squared test is always valid in tables where both marginals are balanced, and that the maximum skewness permitted is related to the maximum value of the bound E*, to its value for tables with at least one balanced marginal and to the minimum value that those marginals must have (in non-balanced tables) for the chi-squared test to be valid.     

Modeling the Adenoma and Serrated Pathway to Colorectal CAncer (ASCCA)

Several colorectal cancer (CRC) screening models have been developed describing the progression of adenomas to CRC. Currently, there is increasing evidence that serrated lesions can also develop into CRC. It is not clear whether screening tests have the same test characteristics for serrated lesions as for adenomas, but lower sensitivities have been suggested. Models that ignore this type of colorectal lesions may provide overly optimistic predictions of the screen‐induced reduction in CRC incidence. To address this issue, we have developed the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model that includes the adenoma‐carcinoma pathway and the serrated pathway to CRC as well as characteristics of colorectal lesions. The model structure and the calibration procedure are described in detail. Calibration resulted in 19 parameter sets for the adenoma‐carcinoma pathway and 13 for the serrated pathway that match the age‐ and sex‐specific adenoma and serrated lesion prevalence in the COlonoscopy versus COlonography Screening (COCOS) trial, Dutch CRC incidence and mortality rates, and a number of other intermediate outcomes concerning characteristics of colorectal lesions. As an example, we simulated outcomes for a biennial fecal immunochemical test screening program and a hypothetical one‐time colonoscopy screening program. Inclusion of the serrated pathway influenced the predicted effectiveness of screening when serrated lesions are associated with lower screening test sensitivity or when they are not removed. To our knowledge, this is the first model that explicitly includes the serrated pathway and characteristics of colorectal lesions. It is suitable for the evaluation of the (cost)effectiveness of potential screening strategies for CRC.     

Simulating space-time random fields with nonseparable Gneiting-type covariance functions

Statistics and Computing - Two algorithms are proposed to simulate space-time Gaussian random fields with a covariance function belonging to an extended Gneiting class, the definition of which...     

Model averaging inconcentration–QT analyses

This article describes how a frequentist model averaging approach can be used for concentration–QT analyses in the context of thorough QTc studies. Based on simulations, we have concluded that starting from three candidate model families (linear, exponential, and Emax) the model averaging approach leads to treatment effect estimates that are quite robust with respect to the control of the type I error in nearly all simulated scenarios; in particular, with the model averaging approach, the type I error appears less sensitive to model misspecification than the widely used linear model. We noticed also few differences in terms of performance between the model averaging approach and the more classical model selection approach, but we believe that, despite both can be recommended in practice, the model averaging approach can be more appealing because of some deficiencies of model selection approach pointed out in the literature. We think that a model averaging or model selection approach should be systematically considered for conducting concentration–QT analyses. Copyright © 2016 John Wiley & Sons, Ltd.     

Comparison of hazard rates for dependent random variables

In this paper, we define and study a new notion for the comparison of the hazard rates of two random variables taking into account their mutual dependence. Properties, applications and the comparison for a data set are given.     

Conditional VAR and Expected Shortfall: A New Functional Approach

We estimate two well-known risk measures, the value-at-risk (VAR) and the expected shortfall, conditionally to a functional variable (i.e., a random variable valued in some semi(pseudo)-metric space). We use nonparametric kernel estimation for constructing estimators of these quantities, under general dependence conditions. Theoretical properties are stated whereas practical aspects are illustrated on simulated data: nonlinear functional and GARCH(1,1) models. Some ideas on bandwidth selection using bootstrap are introduced. Finally, an empirical example is given through data of the S&P 500 time series.     

Fatigue management by truck drivers in real life situations: some suggestions to improve training

Truck driver fatigue is a major safety issue for truck drivers and the public in general. Although training prepares drivers to effectively operate a truck, it tends to minimize the importance of working constraints faced daily on-the-job and thus reduces its impact on safety and effectiveness. With experience, drivers develop skills to combat fatigue. Documenting these skills can contribute to improved training of apprentices. An ethnographic approach was used to better understand the real-life fatigue management skills of truck drivers. Participant observation was used to analyze the activity of apprentices in training and the activity of truck drivers at work. Observations indicated that training focused on time management and regulations, but did not prepare trainees to manage real-life constraints. Experienced drivers were not merely managing time; rather they were managing working constraints (including time) as a whole. To do so, they used two strategies: managing psycho-physical transformations and dynamic work planning. By integrating psycho-physical preoccupations into all aspects of work and by preparing future drivers to face real-life constraints, we could better train and prepare apprentices. Drivers do develop effective skills to combat fatigue which can improve training and better prepare future drivers to face daily constraints. These improvements can have a significant impact on fatigue and safety in the transportation industry.