Restricted Covariance Priors with Applications in Spatial Statistics

We present a Bayesian model for area-level count data that uses Gaussian random effects with a novel type of G-Wishart prior on the inverse variance--covariance matrix. Specifically, we introduce a new distribution called the truncated G-Wishart distribution that has support over precision matrices that lead to positive associations between the random effects of neighboring regions while preserving conditional independence of non-neighboring regions. We describe Markov chain Monte Carlo sampling algorithms for the truncated G-Wishart prior in a disease mapping context and compare our results to Bayesian hierarchical models based on intrinsic autoregression priors. A simulation study illustrates that using the truncated G-Wishart prior improves over the intrinsic autoregressive priors when there are discontinuities in the disease risk surface. The new model is applied to an analysis of cancer incidence data in Washington State.Comment: Published at http://dx.doi.org/10.1214/14-BA927 in the Bayesian Analysis (http://projecteuclid.org/euclid.ba) by the International Society of Bayesian Analysis (http://bayesian.org/

Experiences of Therapists and Occupational Therapy Students Using Video Conferencing in Conduction of Focus Groups

A paucity of literature exists on how to conduct an online focus group. The purpose of this study is to describe and learn from participants’ experiences in using virtual technology in a focus group conducted to refine a low vision assessment. Ten low vision therapists and five master’s level students participated. Two cycles of data collection and analysis occurred, one for focus group transcripts of therapists and another for student replies to a questionnaire. A case-by-case matrix was created and data sorted into three categories including: (1) benefits to using the technology; (2) challenges to using the technology; and (3) suggestions for future use of the technology. Therapists valued communicating with their peers from settings of their choice and students gained satisfaction in facilitating the communication. Optimal data collection with online focus groups requires that researchers be knowledgeable in all the technology features and carefully plan for common technology issues

Queen of Spade

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The School Administrator In The American Novel

The study sought answers to the following questions: (1) How are school administrators portrayed in American novels? (2) Can any trends or patterns be established by an analysis of the portrayals? (3) How do these fictional portrayals compare with descriptions in the professional literature? (4) Are the fictional portrayals stereotypes?;Chapter 1 introduced the topic; examined its significance contending that fictional writers mirror society and, adversely, affect society; listed assumptions and limitations; and defined terms; Chapter 2 provided a survey of related studies. Other cross-discipline studies were cited. Then, studies which emphasized personal characteristics of the administrator, the nature of the job, and stereotyping were examined; Next, sampling, instrumentation, and research procedures were summarized in Chapter 3. The sample consisted of fifty American novels written since 1940 containing references to public or private school principals or assistant principals; superintendents; or college or university deans or presidents. Grounded theory, which is not based on a priori assumptions, was employed in the research. Additionally, content analysis was used in analyzing excerpted passages; The selected novels were examined in Chapter 4 which was organized into subsections: public school administrators, private school administrators, superintendents, college or university deans and presidents. The coding categories devised were demographic characteristics, task areas, leadership styles, organizational theories, and power sources; Chapter 5 summarized the findings, drew conclusions, made recommendations, and offered suggestions for further research. The major conclusions were as follows: (1) the overall portrayal of school administrators was negative; (2) public school administrators were most often depicted in the task areas of pupil and staff personnel; private school administrators in pupil personnel and community school leadership; and college or university administrators in community school leadership, staff, and finances; (3) the leadership style most often employed by the characters was a 9,1 style--a high concern for task and a low concern for people; (4) the administrators were most often portrayed as bureaucrats; (5) the administrators studied most frequently used coercive power; (6) school administrators were not often characters in novels and even less frequently were they heroes; (7) there was often a discrepancy between the novelists\u27 descriptions of school administrators and descriptions in the professional literature; and (8) a stereotype of the school administrator existed

A comparison of the characteristics of Giles County, Tennessee home demonstration homemakers and public housing homemakers and their use of recommended nutrition practices

The purpose of this study was to determine the relationship between the level of nutrition practice use by home demonstration club members and public housing homemakers and compare their personal and family characteristics, method of receiving nutrition information, and interest of homemakers in attending meetings related to foods. Two random samples of 25 each were drawn from the populations of this study included 313 home demonstration club members and 297 public housing homemakers from Giles County. Personal interviews were conducted in the homes of the subjects. Differences between groups of 9 percent or larger were considered to be consequential and were discussed. The study revealed consequential difference between home demonstra-tion and public housing homemaker in several socioeconomic characteristics, number of children, participation in Extension Activities and use of Extension services, location of residents, age groups, marital status, major occupation of husbands, income, educational status, use of mass media, sources and number of sources of help, growing of gardens, church attendance and membership in organization. The findings indicated consequential differences in use of most of the sixteen recommended nutrition practices. Implications, recommendations for use of study finding and recom-mendations for further study also were included

Plums

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Penalised smoothing splines resolve the curvature identifiability problem in age-period-cohort models with unequal intervals

Age-period-cohort (APC) models are frequently used in a variety of health and demographic-related outcomes. Fitting and interpreting APC models to data in equal intervals (equal age and period widths) is nontrivial due to the structural link between the three temporal effects (given two, the third can always be found) causing the well-known identification problem. The usual method for resolving the structural link identification problem is to base a model on identifiable quantities. It is common to find health and demographic data in unequal intervals, this creates further identification problems on top of the structural link. We highlight the new issues by showing that curvatures which were identifiable for equal intervals are no longer identifiable for unequal data. Furthermore, through extensive simulation studies, we show how previous methods for unequal APC models are not always appropriate due to their sensitivity to the choice of functions used to approximate the true temporal functions. We propose a new method for modeling unequal APC data using penalized smoothing splines. Our proposal effectively resolves the curvature identification issue that arises and is robust to the choice of the approximating function. To demonstrate the effectiveness of our proposal, we conclude with an application to UK all-cause mortality data from the Human mortality database.</p