Asymptotically Efficient Estimation of a Bivariate Gaussian–Weibull Distribution and an Introduction to the Associated Pseudo-truncated Weibull

Two important wood properties are stiffness (modulus of elasticity or MOE) and bending strength (modulus of rupture or MOR). In the past, MOE has often been modeled as a Gaussian and MOR as a lognormal or a two or three parameter Weibull. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior of MOE and MOR for the purposes of wood system reliability calculations, we introduce a bivariate Gaussian–Weibull distribution and the associated pseudo-truncated Weibull. We use asymptotically efficient likelihood methods to obtain an estimator of the parameter vector of the bivariate Gaussian–Weibull, and then obtain the asymptotic distribution of this estimator.     

Towards an interactional approach to reflective practice in social work

Reflective practice is a key aspiration within social work; being a reflective practitioner is considered to be a foundational attribute of the social work professional. However, achieving reflective practice is not straightforward. Reflection is inevitably subject to issues of memory and recall, so that the recollection of a case is likely to differ in important ways from the original instance. Moreover, giving an account of an event to one's peers or supervisors involves aspects of justification and self-presentation that may emphasise selectively and ignore key details of the original event, whether through a process of conscious omission or subconscious forgetting. This article reports on a knowledge exchange project that sought to enhance criminal justice social workers’ reflective practice through the use of the Conversation Analytic Role-play Method, an approach that is methodologically and theoretically grounded in the study of talk-in-interaction, drawing on video re-enactments of real encounters between practitioners and service users. We argue that by engaging collaboratively in this way, the practitioners and researchers learned a great deal about how practice in criminal justice social work is ‘done’ and also about the wider context within which criminal justice social work is practised.     

The importance of demographic analyses in state- and local-level policy evaluations: A case study analysis of property taxes in Texas,USA

The reluctance of policy-makers to incorporate detailed demographic analyses in policy analyses often means that population composition is ignored in state and local policy evaluations. This article uses standard demographic projection, standardization and rate decomposition techniques to examine the implications of changing population composition for the property tax revenue base of Texas. The authors find that if current socioeconomic differentials persist into the future, projected compositional changes in the household population of Texas will significantly impact property tax revenues. Thus revenue projections based on aggregate growth and current average property value would seriously overestimate future property tax revenues in Texas because changes in the composition of the population lead to disproportionate growth in households likely to live in lower valued housing unite. The results indicate that the continuing focus of state and local policy-makers on changes in population size alone may be ill-advised and demonstrate the increasing importance of local- and state-level demographic analysis in a period of increasing Federal devolution of service provision.     

An empirically derived typology of mentally ill group home residents.

The classification of clients in terms of psychiatric diagnosis or level of functioning is a logical prerequisite to the conduct of quality of care assessments in mental health care. This article reports on efforts to create a typology of mentally ill group home residents based on a variety of measures of functioning. Subjects for the study come from a probability sample of 253 group home residents in Michigan. A three group typology, derived through cluster analytic procedures, is presented along with-evidence supporting its validity. Implications of the typology for program evaluators and service system planners are briefly addressed.     

Resolving a Multi-Million Dollar Contract Dispute With a Latin Square

The City of New York negotiated a dispute over the performance of new garbage trucks purchased from a vehicle manufacturer. The dispute concerned the fulfillment of a specification in the purchase contract that the trucks load a minimum full-load of 12.5 tons of household refuse. On behalf of the City, but in cooperation with the manufacturer, the City's Department of Sanitation and consulting statisticians tested fulfillment of the contract specification, employing a Latin Square design for routing trucks. We present the classical analysis using a linear model and analysis of variance. We also show how fixed, mixed, and random effect models are useful in analyzing the results of the test. Finally, we take a Bayesian perspective to demonstrate how the information from the data overcomes the difference between the prior densities of the city and the manufacturer for the load capacities of the trucks to result in much closer posterior densities. This procedure might prove useful in similar negotiations. Supplementary material including the data and R code for computations in the article are available online.     

The psychological benefits of exercise in work settings: A review, critique, and dispositional model

Evidence on the psychological effects of exercise on employees is considered. Studies which examined the effect of company-sponsored exercise programmes as well as those examining the more general effect of exercise in work settings are reviewed. It is concluded that the evidence for psychological benefits is equivocal. Due to methodological problems, it is difficult to determine whether exercise is responsible for the positive effects reported. Four personality characteristics which may be responsible for both exercise and psychological reactions to work are considered, and a model is then presented. It was concluded that future studies examining the impact of exercise should consider this dispositional model.     

The discursive structure of the social-technical divide: the example of information systems development1

The social and technical are commonly defined in opposition to each other. Yet technology practitioners are often quite comfortable with the idea that the technical is constitutively social. Drawing on an ethnographic study of a computerised information systems development project, this paper examines various usages of notions of ‘technical’. Attempts to situate the study at the ‘technical core’ of the project were met with a series of rebuffs. ‘Technical’ talk is to be understood as a categorising device which does boundary work. Technical talk invokes and performs a disjunction between networks of social relationships and stipulates a moral order with associated norms for acceptance and transition. The difficulty of penetrating the intelligibility of technical talk is understandable as a struggle in familiarising oneself with the routine social actions of a separate community. In addition, the private sphere of the technical is often distanced in time. The costs involved in journeying into the future are analogous to those of penetrating alien cultures. Ideas of progress and advance are often associated with the invocation of ‘the technical’. These connote a notion of timing which reinforces the distance and difference of—and hence depicts the costs involved in penetrating—removed sets of social relationships.