Beta‐binomial ANOVA for multivariate randomized response data

There is much empirical evidence that randomized response methods improve the cooperation of the respondents when asking sensitive questions. The traditional methods for analysing randomized response data are restricted to univariate data and only allow inferences at the group level due to the randomized response sampling design. Here, a novel beta‐binomial model is proposed for analysing multivariate individual count data observed via a randomized response sampling design. This new model allows for the estimation of individual response probabilities (response rates) for multivariate randomized response data utilizing an empirical Bayes approach. A common beta prior specifies that individuals in a group are tied together and the beta prior parameters are allowed to be cluster‐dependent. A Bayes factor is proposed to test for group differences in response rates. An analysis of a cheating study, where 10 items measure cheating or academic dishonesty, is used to illustrate application of the proposed model.     

Precocity of fine motor control and task context: hitting a ball while stepping

To determine if children under 5 years were able to intercept a moving object while stepping, the authors had 9 3-year-olds hit a ball that the authors dropped from a ramp from 5 heights (1.5, 2.0, 2.5, 3.0, and 3.5 m). The statistical analysis showed that the hand movement times were similar regardless of ball rolling heights and that the hand initiation times were dependent on the ball rolling times. Children under 5 years were able to hit a moving ball, and they performed this hitting according to a temporal coupling between ball displacements and the hand contact with it. The participants' behavior of hitting while stepping supports the idea that the motor system implicitly knows what the cognitive system ignores.     

The error statistical philosopher as normative naturalist

We argue for a naturalistic account for appraising scientific methods that carries non-trivial normative force. We develop our approach by comparison with Laudan’s (American Philosophical Quarterly 24:19–31, 1987, Philosophy of Science 57:20–33, 1990) “normative naturalism” based on correlating means (various scientific methods) with ends (e.g., reliability). We argue that such a meta-methodology based on means–ends correlations is unreliable and cannot achieve its normative goals. We suggest another approach for meta-methodology based on a conglomeration of tools and strategies (from statistical modeling, experimental design, and related fields) that affords forward looking procedures for learning from error and for controlling error. The resulting “error statistical” appraisal is empirical—methods are appraised by examining their capacities to control error. At the same time, this account is normative, in that the strategies that pass muster are claims about how actually to proceed in given contexts to reach reliable inferences from limited data.     

Changes in suicide methods in Quebec between 1987 and 2000: the possible impact of bill C-17 requiring safe storage of firearms

This study presents the changes in the overall and firearm suicide rates for Québec (Canada) before and after Bill C-17, which was implemented to secure safe storage of firearms. It covers 20,009 suicide cases reported to the coroner's office. Interrupted time series analysis is used to compare suicide rates in the two periods. Firearm suicide rates have dropped among males and females, but the downward trends were not significant when compared to those prior to the law. Hanging suicide rates have risen considerably among men and women, but those upward trends did not increase significantly when compared with those preceding the law. The decline in suicide rates involving firearms has not resulted in a parallel decline in overall suicide rates. The analyses suggest that Bill C-17 neither improved the downward trend in firearm suicide, which had already begun before the enactment of the law, nor reduced the upward trend of the overall suicide rate. Correlation analyses between firearm suicide, hanging suicide, and the overall suicide rate suggest that firearm suicide is replaced by hanging suicide among males.     

The intensity of recent and distant life regrets: an integrated model and a large scale survey

The research considers three predictors of the intensity of life regrets: (a) whether the regretted behaviour is an action or a failure to act, (b) the severity of its consequences and (c) the extent to which the behaviour was justified. It is hypothesised that the intensity of recent and distant regrets will be predicted by different combinations of these predictors. Regression analyses on regrets reported by 957 French adults support this hypothesis. The intensity of recent regrets is predicted by the consequences of the behaviour, and especially so for actions. The intensity of distant regrets is predicted by the consequences of the behaviour and by its justification, the effect of justification being stronger for actions than for inactions. These results are discussed in relation to both laboratory and field studies of regret. Copyright © 2007 John Wiley & Sons, Ltd.     

Mentoring Relationships and Programs for Youth

ABSTRACT— Mentoring is one of the most popular social interventions in American society, with an estimated three million youth in formal one-to-one relationships. Studies have revealed significant associations between youth involvement in mentoring relationships and positive developmental outcomes. These associations are modest, however, and depend on several intervening processes. Centrally important is the formation of close, enduring connections between mentors and youth that foster positive developmental change. Effects of mentoring programs likewise typically have been small in magnitude, but they increase systematically with the use of program practices likely to support relationship development. Gaps between research and practice are evident both in the indiscriminate use of the term mentoring in the prevention field and in a focus on the growth and efficiency of mentoring programs at the expense of quality. Continued expansion of effective mentoring will require a better alignment of research and practice.     

Neocortical maturation during adolescence: change in neuronal soma dimension

During adolescence, cognitive abilities increase robustly. To search for possible related structural alterations of the cerebral cortex, we measured neuronal soma dimension (NSD = width times height), cortical thickness and neuronal densities in different types of neocortex in post-mortem brains of five 12-16 and five 17-24 year-olds (each 2F, 3M). Using a generalized mixed model analysis, mean normalized NSD comparing the age groups shows layer-specific change for layer 2 (p < .0001) and age-related differences between categorized type of cortex: primary/primary association cortex (BA 1, 3, 4, and 44) shows a generalized increase; higher-order regions (BA 9, 21, 39, and 45) also show increase in layers 2 and 5 but decrease in layers 3, 4, and 6 while limbic/orbital cortex (BA 23, 24, and 47) undergoes minor decrease (BA 1, 3, 4, and 44 vs. BA 9, 21, 39, and 45: p = .036 and BA 1, 3, 4, and 44 vs. BA 23, 24, and 47: p = .004). These data imply the operation of cortical layer- and type-specific processes of growth and regression adding new evidence that the human brain matures during adolescence not only functionally but also structurally.