Analytical closed-form solution for binary logit regression by categorical predictors

In contrast to the common belief that the logit model has no analytical presentation, it is possible to find such a solution in the case of categorical predictors. This paper shows that a binary logistic regression by categorical explanatory variables can be constructed in a closed-form solution. No special software and no iterative procedures of nonlinear estimation are needed to obtain a model with all its parameters and characteristics, including coefficients of regression, their standard errors and t-statistics, as well as the residual and null deviances. The derivation is performed for logistic models with one binary or categorical predictor, and several binary or categorical predictors. The analytical formulae can be used for arithmetical calculation of all the parameters of the logit regression. The explicit expressions for the characteristics of logit regression are convenient for the analysis and interpretation of the results of logistic modeling.     

A method from the ‘lifeworld’: some possibilities for person centred planning for children in care

This paper describes a method for working with children who are the subjects of care planning and review under the Children Act 1989. The person centred planning method, as it is termed, has been well established in working with adults with special needs but can be extrapolated to encounters with children. It focuses on three fundamental areas: relationship, meaning and narrative. In underscoring these areas, the method restrains the bureaucracy and experience of stigma that is often present for those residing in state care. On a wider plane, the paper argues that the method stands as a veritable example of Habermas's ideas concerning the application of communicative rationality and discursive democracy in social life.     

Developing critical social work in theory and in practice: child protection and communicative reason

This paper argues that a critical analysis of the ideologies that inform contemporary child care has been missing from the 're-focusing debate'. Such an analysis points up the necessity of reasserting a critical social work position in order to provide a basis for reconstructing practice and engaging with other social actors and their ideologies in an open and creative fashion compatible with Habermas' aspiration of 'communicative reason'.     

African American MSW Students: Personal Influences on Social Work Careers and Factors in Graduate School Selection

The research is an empirical examination of who the individuals were that influenced 207 African American respondents to pursue graduate social work education, and what enrollment decision factors (EDFs) led them to select a social work program. Statistically significant relationships between EDFs are also isolated. The purposive sample consisted of MSW graduates from three predominantly White universities in two southeastern states in the United States. Almost 80% were females, the mean age was 44.5 years, and 45% majored in social work as undergraduates. Individuals who reportedly had ‘a great deal of influence’ in their selection of graduate social work education included social work practitioners, family members, and undergraduate professors. The ‘very important’ EDFs included geographical location, type of social work program, class scheduling, and cost of tuition. The strongest EDF correlations were between (1) number of minority students and number of minority faculty (r?=?0.662, p?=?0.000, 0.01 level, 2‐tailed); (2) academic reputation and type of social work program (r?=?0.590, p?=?0.000, 0.01 level, 2‐tailed); and (3) number of minority faculty and school climate toward minorities (r?=?0.523, p?=?0.000, 0.01 level, 2‐tailed). Findings suggest that graduate school recruitment strategies for African Americans and other under‐represented groups should include use of social work practitioners and educators, as well as more informed and deliberate marketing approaches with respect to school curricula and how it translates into future career options.     

On the Use of the Cause Table in Handling Common Cause Events in System Analysis

A method is presented for applying the cause table concept to the problem of common cause events. This method can be regarded as an alternative to the approach in which these events are included directly into the system fault trees. In comparison with this approach, the cause table method offers the advantage of simple fault trees, convenient visibility of the contributions of causes, and the ability to truncate the numerical calculation conveniently by aggregating small terms into an "other" category. Generally speaking, the cause table method can be said to handle common causes at the level of arithmetic (i.e., numbers) rather than at the level of algebra (determining cutsets and frequency equations).     

Re-thinking a systemic approach to child welfare: A critical response to the framework for the assessment of children in need and their families

The Framework for the Assessment of Children in Need was introduced by the Department of Health (England and Wales) in 2000. Offering guidance to social workers in child and family settings, it came as a watershed in three main ways. First, it emphasized the connection between child poverty and developmental delay. Second, it advocated a systemic approach to child welfare by drawing on a number of related theories, including Bronfenbrenner's (1979) model of human development. Third, it overturned a restricted preoccupation with child abuse that had dominated much of child and family social work in the past. These developments aside, the systemic basis of the framework is problematic because it fails to explain how power operates within society. Without this understanding, social workers will not be in a position to tackle the inequalities which the framework rightly targets. This paper seeks to remedy these deficits by drawing on the critical systems theory of Jürgen Habermas.     

Reproducibility of the Dose-Response Curve of Steroid-Induced Cleft Palate in Mice

Pregnant CD-1 mice were exposed to cortisone acetate at doses ranging from 20 to 100 mg/kg/ day on days 10-13 by oral and intramuscular routes. Multiple replicate assays were conducted under identical conditions to assess the reproducibility of the dose–response curve for cleft palate. The data were fitted to the probit, logistic, multistage or Armitage-Doll, and Weibull dose-response model separately for each route of exposure. The curves were then tested for parallel slopes (probit and logistic models) or coincidence of model parameters (multistage and Weibull models). The 19 replicate experiments had a wide range of slope estimates, wider for the oral than for the intramuscular experiments. For all models and both routes of exposure the null hypothesis of equality of slopes was rejected at a significant level of p < 0.001. For the intramuscular group of replicates, rejection of slope equality could in part be explained by not maintaining a standard dosing regime. The rejection of equivalence of dose-response curves from replicate studies showed that it is difficult to reproduce dose-response data of a single study within the limits defined by the dose-response model. This has important consequences for quantitative risk assessment, public health measures, or development of mechanistic theories which are typically based on a single animal bioassay.