Mapping Comparative Empirical Studies of European Social Work

Correspondence to Professor Steven M. Shardlow, Director Salford Centre for Social Work Research, School of Community, Heath Sciences and Social Care, The University of Salford, Allerton Building, Frederick Road, Salford, Greater Manchester M6 6PU, UK. E-mail: S.M.Shardlow{at}Salford.ac.uk Summary This paper reviews the scope of currently published materialsabout comparative empirical social work research within Europe,published in English over a two-decade period (1980–2000).To this end, the paper is divided into four sections. First,an account of the scope and methods used to conduct this review.Second, a brief analysis of non-empirical published materials.Third, in the bulk of the paper, identified comparative studiesare discussed in depth, with a particular focus upon methodologicalissues. Finally, by way of a conclusion, comments are made aboutthe state of contemporary empirical studies within Europeansocial work, and the relationship of these studies to the constructionof social work knowledge. In addition, some suggestions of possiblesites for improvement in respect of comparative empirical researchabout social work in Europe are made.     

Improving School Achievement and Inter‐group Relations for Children Placed at Risk: the Roots and Wings program

Roots and Wings is a comprehensive elementary‐school program designed to ensure that all children achieve world class standards in reading, writing and language arts, mathematics, science, history and geography; and can apply their knowledge to solve real‐world problems. Critical to these goals is increasing the achievement of students placed at‐risk as a consequence of poverty, disabilities, language problems, or other factors. Roots and Wings extensively employs cooperative learning to promote student motivation, socialization, appreciation of diversity, and academic achievement. Although cooperative learning offers a variety of potential benefits, it can be challenging to use for teachers and students more accustomed to traditional methods. This paper presents research in inner‐city elementary schools using the Roots and Wings design and identifies several factors that facilitate the change process and quality of cooperative classroom activities.     

High-dimensional regression in practice: an empirical study of finite-sample prediction,variable selection and ranking

Penalized likelihood approaches are widely used for high-dimensional regression. Although many methods have been proposed and the associated theory is now well developed, the relative efficacy of different approaches in finite-sample settings, as encountered in practice, remains incompletely understood. There is therefore a need for empirical investigations in this area that can offer practical insight and guidance to users. In this paper, we present a large-scale comparison of penalized regression methods. We distinguish between three related goals: prediction, variable selection and variable ranking. Our results span more than 2300 data-generating scenarios, including both synthetic and semisynthetic data (real covariates and simulated responses), allowing us to systematically consider the influence of various factors (sample size, dimensionality, sparsity, signal strength and multicollinearity). We consider several widely used approaches (Lasso, Adaptive Lasso, Elastic Net, Ridge Regression, SCAD, the Dantzig Selector and Stability Selection). We find considerable variation in performance between methods. Our results support a “no panacea” view, with no unambiguous winner across all scenarios or goals, even in this restricted setting where all data align well with the assumptions underlying the methods. The study allows us to make some recommendations as to which approaches may be most (or least) suitable given the goal and some data characteristics. Our empirical results complement existing theory and provide a resource to compare methods across a range of scenarios and metrics.     

Practical guide to sample size calculations: non‐inferiority and equivalence trials

A sample size justification is a vital part of any trial design. However, estimating the number of participants required to give a meaningful result is not always straightforward. A number of components are required to facilitate a suitable sample size calculation. In this paper, the steps for conducting sample size calculations for non‐inferiority and equivalence trials are summarised. Practical advice and examples are provided that illustrate how to carry out the calculations by hand and using the app SampSize. Copyright © 2015 John Wiley & Sons, Ltd.     

Practical guide to sample size calculations: superiority trials

A sample size justification is a vital part of any investigation. However, estimating the number of participants required to give meaningful results is not always straightforward. A number of components are required to facilitate a suitable sample size calculation. In this paper, the steps for conducting sample size calculations for superiority trials are summarised. Practical advice and examples are provided illustrating how to carry out the calculations by hand and using the app SampSize. Copyright © 2015 John Wiley & Sons, Ltd.     

Practical guide to sample size calculations: an introduction

A sample size justification is a vital step when designing any trial. However, estimating the number of participants required to give a meaningful result is not always straightforward. A number of components are required to facilitate a suitable sample size calculation. In this paper, the general steps are summarised for conducting sample size calculations with practical advice and guidance on how to utilise the app SampSize. Copyright © 2015 John Wiley & Sons, Ltd.     

Role versatility among men who have sex with men in urban Peru

Role versatility refers to the practice in which individual men who have sex with men (MSM) play both insertive and receptive sexual roles over time. Versatility has been thought to be relatively uncommon among Latin American MSM but possibly rising. Versatility has also been shown to be a potentially large population-level risk factor for HIV infection. In this study we examine the correlates of versatile behavior and identity among 2,655 MSM in six Peruvian cities. Versatile behavior with recent male partners was found in 9% of men and versatile ("moderno") identity was reported by 16%. Significant predictors included high education, white-collar occupation, sex work, and residence in Lima. Age was not significant in any analysis. Since sex work is negatively correlated with other predictors, versatile men appear to comprise two distinct sub-populations. Insertive-only men appear to play a strong role in bridging the HIV epidemic between MSM and women.     

When do simpler sexual behavior data collection techniques suffice? An analysis of consequent uncertainty in HIV acquisition risk estimates

The "gold standard" for evaluating human immunodeficiency virus (HIV) prevention programs is a partner-by-partner sexual behavior assessment that elicits information about each sex partner and the activities engaged in with that partner. When collection of detailed partner-by-partner data is not feasible, aggregate data (e.g., total numbers of partners and acts of various types) must suffice. Lack of specificity in the primary data often translates into uncertainty in modeled outcomes, such as participants' risk of HIV acquisition. To our knowledge, no previous study has attempted to quantify this uncertainty. The results of the present analysis of the risk of HIV acquisition by men vacationing in Key West indicate that the use of aggregate rather than partner-by-partner data introduced relatively little uncertainty into the HIV risk estimates. Collection of aggregate data is a viable alternative to detailed partner-by-partner data, at least in some circumstances.