Modeling population and subject-specific growth in a latent trait measured by multiple instruments over time using a hierarchical Bayesian framework

Psychometric growth curve modeling techniques are used to describe a person’s latent ability and how that ability changes over time based on a specific measurement instrument. However, the same instrument cannot always be used over a period of time to measure that latent ability. This is often the case when measuring traits longitudinally in children. Reasons may be that over time some measurement tools that were difficult for young children become too easy as they age resulting in floor effects or ceiling effects or both. We propose a Bayesian hierarchical model for such a scenario. Within the Bayesian model we combine information from multiple instruments used at different age ranges and having different scoring schemes to examine growth in latent ability over time. The model includes between-subject variance and within-subject variance and does not require linking item specific difficulty between the measurement tools. The model’s utility is demonstrated on a study of language ability in children from ages one to ten who are hard of hearing where measurement tool specific growth and subject-specific growth are shown in addition to a group level latent growth curve comparing the hard of hearing children to children with normal hearing.KEYWORDS: Bayesian hierarchical models, psychometric modeling, language ability, growth curve modeling, longitudinal analysis     

DO BETTER INFORMED INVESTORS ALWAYS DO BETTER? A BUYBACK PUZZLE

We explore the value of private investment information using data from a singular source: auctions of yearling racehorses. Horse breeders possess superior information about their own horses and have strong financial incentives to buy the best of these back at auction. However, those they repurchase subsequently perform significantly worse on average, earning 30% less at the racetrack than horses purchased by outsiders. Moreover, this underperformance is concentrated in male horses, despite these being purchased exclusively for racing purposes. These puzzling findings cannot be explained by differences in horse risk or breeder abilities, or by nonfinancial objectives, or by behavioral or selection biases. (JEL G02, G11, G14, L83, D44)     

Knowledge Brokering: The missing link in the evidence to action chain?

Transferring health care research into policy and practice is a messy and complex process which both policymakers and researchers can struggle with. A potential solution is to use individuals or organisations as knowledge brokers. Using a range of literature, this paper explains the theory behind knowledge brokering, identifies three models of brokering and explores the challenges of brokering. We suggest that clarifying these factors is a significant step towards planning well designed and rigorously evaluated brokering interventions. We also suggest that a clearly defined theoretical framework could help us to find out more about how brokering works and its effectiveness.     

The secular city and the Christian corpus

Abstract

Beginning with a discussion of Fritz Lang's ‘Metropolis’, this paper considers the rise of the city from a theological perspective. The ideal of the modern city was, it is argued, a secularised version of the City of God: the city was to be a place where all human desires might be met, a city without a church because the moral perfection of each human being has been fulfilled. The advent of the postmodern city of consumerist desire undermines this secular dream, and opens a space for theologians to frame alternative visions of cities of erotic participatory desire.     

Final report of the Color Additive Scientific Review Panel

The Color Additives Scientific Review Panel considered whether there was information sufficient to perform a carcinogenic risk assessment on the colors D&C Red No. 19 (R-19), D&C Red No. 37 (R-37), D&C Orange No. 17 (O-17), D&C Red No. 9 (R-9), D&C Red No. 8 (R-8) and FD&C Red No. 3 (R-3) and to evaluate the assessments sent to FDA as part of the petitions for use of the colors for drug and external uses by the Cosmetic, Toiletry and Fragrance Association (CTFA). There is a lack of human data concerning the colors for making a human health assessment, so the assessments are based upon the extrapolation of animal data. The risk assessments are determined for exposure to single chemicals. Excluded from consideration are possible effects from exposure to multiple chemicals, such as co-carcinogenesis, promotion, synergism, antagonism, etc. In the light of recent efforts in establishing a consensus in risk assessment, the Panel has determined that the CTFA assessments for R-10, O-17, and R-9 are consistent with present acceptable usages, although it questions some of the assumptions used in the assessments. The Panel identified a number of general assumptions made, and discusses their validity, their impact on total uncertainty, and the potential options to address the gaps in understanding that necessitate the assumption. The Panel also derived revised risk estimates using more "reasonable" assumptions than "worst-case" situations, for 90th percentile and average exposure. For those assumptions that are easily quantifiable, the Panel's estimates are less than an order of magnitude lower than the CTFA risk estimates, indicating that the underestimates and overestimates of the CTFA risk estimates tend to balance each other. The impact of most of the assumptions is not quantifiable. The assessment for R-3 is complicated by the fact that there is no good skin penetrance study for this color. It was assumed that the penetrance is similar to that of another water-soluble xanthene color, R-19. It is expected that the absorption of the color is not likely to exceed that of the smaller molecule, R-19. Therefore, the risk estimates are similar to the CTFA estimates, but with different reasoning. The estimates for R-8 and R-37 are different from the others in that there is a lack of any exposure or toxicological information on these colors.(ABSTRACT TRUNCATED AT 400 WORDS)     

Planning for permanency planning in foster care

The perceived severity of the problem of “drift” in the foster care system has encouraged agencies nationwide to accept permanency planning, but perhaps with limited attention to the planning process. This article examines the phenomenon of permanency planning from a planning perspective by focusing on: (a) definition of the permanency planning problem, (b) understanding of issues relevant to permanency planning (caseworker, program and systemic), (c) appreciation of the operational context (political, economic and social factors), and (d) evaluation of available options and possible consequences in developing or improving a permanency planning program. Permanency planning is not a simple, ready-made program applicable to any situation; it involves coordinated efforts by workers, service systems, and society in general, and requires time, commitment and resources. Successful planning for permanency planning can permit more children to grow up in homes providing continuity and stability.     

Community corrections officers' attributions for sexual offending against children

The present research examined gender differences in community corrections officers' (CCOs') attributions for child sexual offending. Eighty-five CCOs were asked to write down the reasons why they thought men sexually abused children, and then rate their reasons using Benson's Attributional Dimensions Scale. The results found that CCOs' reasons regarding why men sexually abuse children strongly paralleled current scientific theories on the etiology of child sexual abuse. Also, significant gender differences were found regarding the frequency with which participants cited certain types of reasons for child sexual abuse. Female CCOs were more likely to cite power and control as a reason, while male CCOs were more likely to cite psychopathology as a reason for child sexual abuse. No other gender differences were found. The research, clinical, and educational implications pertaining to these findings are discussed.