A test for multivariate structure

We present a test for detecting 'multivariate structure' in data sets. This procedure consists of transforming the data to remove the correlations, then discretizing the data and, finally, studying the cell counts in the resulting contingency table. A formal test can be performed using the usual chi-squared test statistic. We give the limiting distribution of the chi-squared statistic and also present simulation results to examine the accuracy of this limiting distribution in finite samples. Several examples show that our procedure can detect a variety of different types of structure. Our examples include data with clustering, digitized speech data, and residuals from a fitted time series model. The chi-squared statistic can also be used as a test for multivariate normality.     

A meta-analytic review of leadership impact research: Experimental and quasi-experimental studies

In this study we set out to conduct a comprehensive quantitative research analysis of literature reporting results on the causal impact of leadership by focusing on examining what we refer to as ‘leadership interventions.’ We defined leadership interventions as those studies where the researcher overtly manipulated leadership as the independent variable through training, assignment, scenario or other means. Our focus included both examining experimental and quasi-experimental as well as lab and field studies conducted in public and private organizations. Our goal was to address a simple question: do leadership interventions have the intended impact and if so to what degree? We conducted a comprehensive review of the published and unpublished literature and uncovered 200 lab and field studies that met our criterion as leadership intervention studies. We report here the findings of a series of meta-analyzed effects comparing the relative impact of leadership interventions across intervention types, leadership theories, and several common dependent variables. Overall, leadership interventions produced a 66% probability of achieving a positive outcome versus a 50–50 random effect for treatment participants, but this effect varied significantly when assessing moderators such as type of leadership theory.     

An analysis of pulsation periods of long period variable stars

Summary.  We report the results of a period change analysis of time series observations for 378 pulsating variable stars. The null hypothesis of no trend in expected periods is tested for each of the stars. The tests are non-parametric in that potential trends are estimated by local linear smoothers. Our testing methodology has some novel features. First, the null distribution of a test statistic is defined to be the distribution that results in repeated sampling from a population of stars. This distribution is estimated by means of a bootstrap algorithm that resamples from the collection of 378 stars. Bootstrapping in this way obviates the problem that the conditional sampling distribution of a statistic, given a particular star, may depend on unknown parameters of that star. Another novel feature of our test statistics is that one-sided cross-validation is used to choose the smoothing parameters of the local linear estimators on which they are based. It is shown that doing so results in tests that are tremendously more powerful than analogous tests that are based on the usual version of cross-validation. The positive false discovery rate method of Storey is used to account for the fact that we simultaneously test 378 hypotheses. We ultimately find that 56 of the 378 stars have changes in mean pulsation period that are significant when controlling the positive false discovery rate at the 5% level.     

Using social theory to leap over historical contingencies: A comment on Robinson

Conclusion To be fair to Robinson, it is worth mentioning that he does offer a number of qualifications to his thesis. He tries to avoid excessive determinism and at one point suggests: A satisfactory account should not imply an evolutionary notion and should leave open the possibility of historic discontinuities and of contingencies that generate alternative pathways of development, including alternative futures. In other words, maybe this embryonic TNS will never progress beyond its current stage or perhaps it will continue to grow but it will never become a real state. But the main thrust of Robinson’s account is strongly deterministic. In fact, he does not consider a single factor that might impede the unity of the global bourgoisie or derail transnational state formation. In a sense, Robinson’s mistake is that he has tried to derive a theoretical solution to a concrete problem that global capitalism has not yet solved in practice. While it might well be a logical step for capitalist elites to create a Transnational State, it is always risky to attribute too much rationality to an order that is notorious for its contradictions.     

Relationship between job control, work pressure and strain: studies in the USA and in The Netherlands

The purpose of this study was to test a model of job control, work pressure and strain in two samples in the USA and in The Netherlands. According to the proposed model, work pressure has a mediating role between job control and worker strain. The present model specifies three types of job control: task or instrumental control, conceptual or resource control, and decision organization control. Task and resource control are assumed to reduce the stressor of work pressure which, in turn, is related to high strain. Organization control is assumed to be positively related to work pressure. The model was tested in two samples : one US sample of 273office employees and one Dutch sample of 958 employees in a variety of jobs. The same measure of job control was used in both samples. Resultspartially confirm the proposed model. As predicted by the proposed model, high task control was related to low work pressure, whereas high organization control was related to high work pressure. The effects of task control and organization control on strain were mediated by work pressure for the measure of anxiety in the US sample and for the measure of stress in the Dutch sample. However, the mediating effect of work pressure was not found for job satisfaction in both samples, for the measure of mood disturbances in the US sample and for the measure of sick days in the Dutch sample. The proposed model is only partially confirmed by the results. These results confirm the importance of differentiating between different dimensions of job control.     

Schedule Recovery: Unplanned Absences in Service Operations*

The U.S. service sector loses 2.3% of all scheduled labor hours to unplanned absences, but in some industries, the total cost of unplanned absences approaches 20% of payroll expense. The principal reasons for unscheduled absences (personal illness and family issues) are unlikely to abate anytime soon. Despite this, most labor scheduling systems continue to assume perfect attendance. This oversight masks an important but rarely addressed issue in services management: how to recover from short‐notice, short‐term reductions in planned capacity. In this article, we model optimal responses to unplanned employee absences in multi‐server queueing systems that provide discrete, pay‐per‐use services for impatient customers. Our goal is to assess the performance of alternate absence recovery strategies under various staffing and scheduling regimes. We accomplish this by first developing optimal labor schedules for hypothetical service environments with unreliable workers. We then simulate unplanned employee absences, apply an absence recovery model, and compute system profits. Our absence recovery model utilizes recovery strategies such as holdover overtime, call‐ins, and temporary workers. We find that holdover overtime is an effective absence recovery strategy provided sufficient reserve capacity (maximum allowable work hours minus scheduled hours) exists. Otherwise, less precise and more costly absence recovery methods such as call‐ins and temporary help service workers may be needed. We also find that choices for initial staffing and scheduling policies, such as planned overtime and absence anticipation, significantly influence the likelihood of successful absence recovery. To predict the effectiveness of absence recovery policies under alternate staffing/scheduling strategies and operating environments, we propose an index based on initial capacity reserves.     

Domestic violence in veterans with posttraumatic stress disorder who seek couples therapy

Domestic violence rates among veterans with posttraumatic stress disorder (PTSD) are higher than those of the general population. Individuals who have been diagnosed with PTSD who seek couples therapy with their partners constitute an understudied population. Self-report measures of domestic violence, relationship satisfaction, and intimacy were administered at intake to 179 couples seeking relationship therapy at a Veterans Affairs clinic. Couples in which the veteran was diagnosed with combat-related PTSD were compared with two other groups based on the veteran's primary diagnosis (depression, adjustment disorder/V-code). Both the PTSD- and depression-diagnosed veterans perpetrated more violence than did those with adjustment/V-code diagnoses. Domestic violence rates among depressed and PTSD-diagnosed veterans were much higher than those found in previous research. Implications for assessment and treatment are discussed.     

ENGAGING COMMUNITY IN A CYCLE OF PRAXIS

This study employed an action research model known as the community wellness cycle of praxis in research with culturally diverse community members from the St Albans region (Melbourne, Australia). The major aim of the study was to gain a theoretical and pragmatic understanding of well-being from a multicultural perspective. In order to meet this aim, a qualitative study was designed to find out (1) What are the community ideals; needs; and strengths of residents of St Albans, and (2) What actions can be undertaken to improve the well-being of the community? The research involved focus groups with a total of 29 Anglo, Maltese, Vietnamese and Italian community members. The first research question was addressed by asking community members systematically about positive and negative aspects of personal, relational and collective well-being. The second research question was addressed by asking community members to generate ideas on what could be done to improve well-being and by identifying issues of concern that emerged throughout the research. The issues identified by participants offer a rich picture of community ideals, strengths and needs, as well as possible actions that could improve personal, relational and collective wellness in St Albans.

Cette étude utilise un approche de recherche action connu sous le nom du cycle de bien-être de praxis de recherche avec des membres culturellement varies dans un banlieue de Melbourne (Australie). Le but principal de l’étude était de comprendre théoriquement et pragmatiquement bien-être dans d'une perspective multiculturelle. Dans ce perspective étude qualitative a été conçue pour identifier (1) ce que sont les opinions des groupes diverses; leurs besoins et leurs atouts, et (2) de quelles actions peuvent être entreprises affin d améliorer le bien-être de ces groupes? La recherche a utilisé 29 Anglo-Australiens, Maltais, Vietnamiens et Italiens. Les premières questions ce sont posées a propos des aspects positifs et négatifs de bien-être individuel et collectif. Ensuite des questions ont été demandé à propos des idées sur ce qui on pourrait être fait pour améliorer le bien-être et en identifiant leurs soucis. Les soucis identifiées par les participants offrent une image riche des images et des représentations leurs atouts leurs, aussi bien que les actions qui pourraient améliorer le bien-être individuel et collective.     

The potential of asset‐based development strategies for poverty alleviation in Sub‐Saharan Africa

Ssewamala FM, Sperber, ES, Zimmerman JM, Karimli L. The potential of asset‐based development strategies for poverty alleviation in Sub‐Saharan Africa Int J Soc Welfare 2010: 19: 433–443 © 2010 The Author(s), Journal compilation © 2010 Blackwell Publishing Ltd and International Journal of Social Welfare. This article explores the potential of a relatively new approach to social development as a poverty alleviation strategy in Sub‐Saharan Africa (SSA): asset‐based development, an integrated approach to human, social, and economic capital formation. It considers the theoretical framework guiding asset‐based development and the accompanying set of programmatic and policy‐level tools for poverty alleviation in SSA. After considering the recent historical and theoretical contexts of the approach, the authors examine the potential of asset‐based development programs, specifically savings‐led microfinance programs for the poor, to engender development and, more specifically, poverty alleviation in the region. Major challenges and directions for future research are presented.     

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