Enriching Students’ Conceptual Understanding of Confidence Intervals: An Interactive Trivia-Based Classroom Activity

Confidence intervals provide a way to determine plausible values for a population parameter. They are omnipresent in research articles involving statistical analyses. Appropriately, a key statistical literacy learning objective is the ability to interpret and understand confidence intervals in a wide range of settings. As instructors, we devote a considerable amount of time and effort to ensure that students master this topic in introductory courses and beyond. Yet, studies continue to find that confidence intervals are commonly misinterpreted and that even experts have trouble calibrating their individual confidence levels. In this article, we present a 10-min trivia game-based activity that addresses these misconceptions by exposing students to confidence intervals from a personal perspective. We describe how the activity can be integrated into a statistics course as a one-time activity or with repetition at intervals throughout a course, discuss results of using the activity in class, and present possible extensions. Supplementary materials for this article are available online.     

Analysis of the implementation of ergonomic design at the new units of an oil refinery

Ergonomic design is the adaptation of working conditions to human limitations and skills in the physical design phase of a new installation, a new working system, or new products or tools. Based on this concept, the purpose of this work was to analyze the implementation of ergonomic design at the new industrial units of an oil refinery, using the method of Ergonomic Workplace Assessment. This study was conducted by a multidisciplinary team composed of operation, maintenance and industrial safety technicians, ergonomists, designers and engineers. The analysis involved 6 production units, 1 industrial wastewater treatment unit, and 3 utilities units, all in the design detailing phase, for which 455 ergonomic requirements were identified. An analysis and characterization of the requirements identified for 5 of the production units, involving a total of 246 items, indicated that 62% were related to difficult access and blockage operations, while 15% were related to difficulties in the circulation of employees inside the units. Based on these data, it was found that the ergonomic requirements identified in the design detailing phase of an industrial unit involve physical ergonomics, and that it is very difficult to identify requirements related to organizational or cognitive ergonomics.     

Fathers’ Childcare: The Differences Between Participation and Amount of Time

The main research question of this article was whether and how predictors of fathers’ participation in childcare, defined as zero versus more than zero minutes of childcare, differed from predictors of participating fathers’ amount of time on childcare, measured as minutes on the survey day. The sample was drawn from the Multinational Time Use Study (MTUS) and covered surveys from ten industrialised countries from 1987 to 2005. Results showed that there were some similarities, but also remarkable differences between factors influencing participation in childcare and factors affecting participating fathers’ time spent with children. Thus they call for caution regarding findings from existing studies not distinguishing participation from participating fathers’ childcare minutes.     

Unpacking “the pimp case”: Aging black masculinity and grandchild placement in the child welfare system

The child welfare system is responsible for identifying long-term caregivers for children whose biological parents are unable or unwilling to care for them. Although grandparents are increasingly identified as custodians for their grandchildren, little is known about how grandparents are assessed by state actors. Using ethnographic data, this article unpacks the failure of one 63-year-old African American grandfather and his wife to gain custody of his grandson from foster care. This case–known informally as ‘the pimp case’ because of the unverified but widely accepted belief that he had earned income through sexual solicitation–illustrates how men's aging bodies and histories undermine their efforts to be seen as competent caregivers. This article shows how this grandfather's aging body and its perceived limitations became problematic, how his illegitimate social history was at issue, how their family form as grandparents (and thus, non-parents) was deemed illegitimate, and how these came together to mark race, class, and gender in interrelated–but also contradictory–ways.     

Longitudinal Penalized Functional Regression for Cognitive Outcomes on Neuronal Tract Measurements

We describe and analyze a longitudinal diffusion tensor imaging (DTI) study relating changes in the microstructure of intracranial white matter tracts to cognitive disability in multiple sclerosis patients. In this application the scalar outcome and the functional exposure are measured longitudinally. This data structure is new and raises challenges that cannot be addressed with current methods and software. To analyze the data, we introduce a penalized functional regression model and inferential tools designed specifically for these emerging types of data. Our proposed model extends the Generalized Linear Mixed Model by adding functional predictors; this method is computationally feasible and is applicable when the functional predictors are measured densely, sparsely or with error. An online appendix compares two implementations, one likelihood-based and the other Bayesian, and provides the software used in simulations; the likelihood-based implementation is included as the lpfr() function in the R package refund available on CRAN.