Automatic breakpoint detection for retrospective cumulative sum charts

Cumulative sum (cusum) methods can be used for monitoring processes and for retrospective (historical) data analysis. Most software only provides the former. The comment by Williamson that retrospective cusum analysis is a neglected area is still true. Though not in vogue, retrospective cusum analysis is useful for investigations such as benchmarking of processes, identifying causes of process decay, selecting reference data sets for typicality studies, and reporting of historical data. Even those texts which cover retrospective analyses, usually ignore the question of identifying multiple points of change (breakpoints), and present essentially manual methods for assessing single breakpoints. Most users of statistical methods want software solutions that are easy to use and require little user intervention or interpretation. Direct implementation of manual method does not give a user robust solution. Problems are illustrated. Attempts to use monitoring CuSums in retrospective analysis can also lead to errors. A practical recursive method is presented for breakpoint identification and significance assessment, which can be automated. Copyright © 2002 John Wiley & Sons, Ltd.     

Marital Harmony and Conflict: Links to Infants' Emotional Regulation and Cardiac Vagal Tone

This study is an investigation of linkages between marital quality (conflict and harmony) and infants' emotional and physiological regulation: It was hypothesized that infants exposed to greater levels of marital conflict would demonstrate lower levels of emotional and physiological regulation. Fifty‐six low‐risk infants and their mothers attended a laboratory session when infants were 6 months of age. A baseline EKG was gathered to assess infants' cardiac vagal tone and the Bayley Scales of Infant Development and Behavior Rating Scales were administered. Mothers also completed Braiker and Kelley's (1979) marital quality questionnaire. Consistent with past research with preschoolers, marital conflict was found to be linked to lower levels of emotion regulation in infants. However, unlike past research (Gottman & Katz, 1989), results indicated that marital conflict was associated with lower levels of cardiac vagal tone in infants as opposed to higher levels of vagal tone among preschoolers. These findings are explained in terms of a possible developmental alteration in the link between marital conflict and vagal tone from early infancy to later childhood. Findings also have important implications for understanding the potential impact of the early marital relational context for infants emerging regulatory abilities.     

Small Area Estimation via Multivariate Fay–Herriot Models with Latent Spatial Dependence

The Fay–Herriot model is a standard model for direct survey estimators in which the true quantity of interest, the superpopulation mean, is latent and its estimation is improved through the use of auxiliary covariates. In the context of small area estimation, these estimates can be further improved by borrowing strength across spatial regions or by considering multiple outcomes simultaneously. We provide here two formulations to perform small area estimation with Fay–Herriot models that include both multivariate outcomes and latent spatial dependence. We consider two model formulations. In one of these formulations the outcome‐by‐space dependence structure is separable. The other accounts for the cross dependence through the use of a generalized multivariate conditional autoregressive (GMCAR) structure. The GMCAR model is shown, in a state‐level example, to produce smaller mean square prediction errors, relative to equivalent census variables, than the separable model and the state‐of‐the‐art multivariate model with unstructured dependence between outcomes and no spatial dependence. In addition, both the GMCAR and the separable models give smaller mean squared prediction error than the state‐of‐the‐art model when conducting small area estimation on county level data from the American Community Survey.     

Cultivating citizen science for all: ethical considerations for research projects involving diverse and marginalized populations

ABSTRACT

In this paper we argue that investigators using citizen science should attend, as much as possible, to certain ethical considerations when conceptualizing projects by embracing 1) inclusivity (finding ways to include those who have traditionally been excluded), 2) adaptation (modifying projects to provide greater opportunities for varied participation), 3) sensitivity (ensuring projects take into account and respect cultural traditions and beliefs), 4) safety (protocols that protect the physical, psychological, and cultural safety of citizen scientists and society at large), and 5) reciprocity (benefits for citizen scientists). These recommendations are particularly important when engaging in collaborative or co-created citizen science projects with marginalized groups. We provide examples of how citizen science projects can be designed and adapted in ways that ensure that they follow The Golden Rule, and make them appealing to, and achievable for, a greater number of individuals in our diverse global society.     

Gender and the Mental–Physical Health Connection Among U.S. Adults

Using data from the 1995, 1998, and 2001 panels of Aging, Status, and Sense of Control (ASOC) Survey, we examine gender differences in the relationship between self‐rated physical health and mental health over time (n = 2,543). Gender‐stratified path models highlight how the nature of the mental–physical health relationship changes when we use indicators of mental health that have traditionally been labeled as female sensitive (depression) or male sensitive (heavy drinking). Results show that women and men are similar in that mental health has a stronger effect on physical health than the reverse. However, this is only the case when we use gender‐sensitive measures of mental distress: Men who drink heavily and women who are depressed report poorer self‐rated physical health over time, while heavy drinking for women and depression for men have no significant effects on their self‐rated physical well‐being. These results provide evidence of a health process that is gendered in its expression but more universal in its outcome—the exact measure might vary, but men and women alike are physically harmed by mental health problems.     

Research note: imputing large group averages for missing data,using rural-urban continuum codes for density driven industry sectors

Understanding the effects and consequences of missing data imputation is vital to the ability to obtain meaningful and reliable statistics and coefficients in the examination of any quantitatively-based phenomena. Over time a series of sophisticated methods have been developed to handle the issue of missing data imputation however, these sophisticated methods may not always be appropriate or attainable. In these specific cases more traditional approaches to missing data imputation must be employed and driven by the research project, theoretical framework, and the data. In this research note we offer a brief account of one such instance, implementing a large-group mean imputation approach to handling missing data. The analysis is drawn from a much larger project and shows the effect of proper group selection in terms of mean imputation using a cross-validation approach based on the imputed data’s relation to known values. Ultimately, the results show that the use of Rural-Urban Continuum codes are superior to currently used group-means in the U.S., thus introducing a new, and more efficient, approach to the handling of missing data using group-mean imputation.     

Metropolitan Influence and Land Use Competition in Potential Biomass Crop Production: A Spatial Demographic Analysis

Biomass is one alternative energy source that is currently being investigated to combat the growing U.S. dependence on foreign oil. In this study, we explore where traditional farming practices and metropolitan influence will compete for land use against farmland located in optimal biomass crop production zones. To date, no consideration of the impact of urbanization and human development has been taken into account. Here we make a take a seminal approach to examining this relationship given previous analyses. We use overlapping LISA statistics to identify significant clusters of counties facing competition for land use. To measure competition for land use in counties located within biomass zones circa 2000, we use population growth and housing data from Census Bureau estimates, farmland data from the Census of Agriculture, and remotely sensed land use/cover data from the United States Geological Survey. The implications of these factors and how they will potentially affect biomass crop production are discussed.     

What was the Dust Bowl? Assessing contemporary popular knowledge

This article reports on an assessment of contemporary popular knowledge and perceptions of the American Dust Bowl of the 1930s. In a region prone to recurrent drought and evolving resource issues such as the depletion of the Ogallala Aquifer, it follows that knowledge of the Dust Bowl can contribute to understanding and dealing with contemporary and future challenges to the human–environment dynamic of the region. An age-stratified sample of residents from 93 Great Plains counties provided their understandings of the three Dust Bowl concepts (era, event, and region) via questionnaire. When compared with the academic record on the subject, significant variation between respondent age groups was identified. Successively, older generations of the historic Dust Bowl region maintain higher degrees of knowledge than their younger counterparts, regarding this exceptional chapter of American environmental history. This record of knowledge erosion not only speaks to the necessity of enhancing Dust Bowl educational resources, but can be utilized to underscore the salience of studying and documenting adaptive strategies to drought on the American Great Plains.