Computation of determinantal subset influence in regression

One of the important goals of regression diagnostics is the detection of cases or groups of cases which have an inordinate impact on the regression results. Such observations are generally described as influential. A number of influence measures have been proposed, each focusing on a different aspect of the regression. For single cases, these measures are relatively simple and inexpensive to calculate. However, the detection of multiple-case or joint influence is more difficult on two counts. First, calculation of influence for a single subset is more involved than for an individual case, and second, the sheer number of subsets of cases makes the computation overwhelming for all but the smallest data sets.Barrett and Gray (1992) described methods for efficiently examining subset influence for those measures that can be expressed as the trace of a product of positive semidefinite (psd) matrices. There are, however, other popular measures that do not take this form, but rather are expressible as the ratio of determinants of psd matrices. This article focuses on reducing the computation for the determinantal ratio measures by making use of upper and lower bounds on the influence to limit the number of subsets for which the actual influence must be explicitly determined.     

Multiple decision rules for comparing several populations with a fixed known standard

Independent observations are available from k univariate distributions indexed by a real parameter θ. It is desired to select that distribution with the largest parameter value unless this value is smaller than some fixed standard θ₀ in which case no distribution is to be selected. Various single-stage procedures for this (k+l)-decision problem are discussed, using indifference zone, decision theoretic, Bayesian, and subset selection approaches.     

Should Dsm Be the Basis for Teaching Social Work Practice in Mental Health? Yes!

Abstract

Point/Counterpoint is a regular feature of the Journal of Social Work Education. Its purpose is to provide a vehicle for the expression of contrasting views on controversial topics in social work education. Our goal is to illuminate important debates and explore the diverse perspectives that are shaping social work education.

In each issue of the Journal several social work educators are invited to comment on a topic about which they have differing viewpoints. The commentators are given an opportunity to make a brief rebuttal. In this issue, Janet Williams (Professor, Columbia University College of Physicians and Surgeons), Robert Spitzer (Professor, Columbia University College of Physicians and Surgeons), Herb Kutchins (Professor, California State University, Sacramento), and Stuart Kirk (Professor, University of California, Los Angeles) address the question: Should DSM be the basis for teaching social work practice in mental health?     

Young,anchored and free? Examining the dynamics of early housing pathways in Australia

Young people are remaining in the parental home for longer, and returning there more often, before attaining residential independence. In Australia, these patterns have prompted concerns about a ‘boomerang generation’ whose housing aspirations and decisions have either been directly questioned, or viewed as symptomatic of broader affordability issues. Employing a longitudinal perspective, we argue that early residential pathways reflect a mix of stable and dynamic influences involving individuals, their families, and their broader relationships. Using data from a large cohort (n = 2082) of young Australians participating in the ‘Our Lives’ research project, we examine housing pathway formation between the ages of 12/13 and 21/22. Events such as parental union dissolution or partnership formation were found to encourage home leaving, whilst being employed at a younger age and having grown up rurally predicted both leaving and remaining out of home. Close, supportive relationships with family and friends served to ‘anchor’ respondents at home for longer, and parental socioeconomic resources enabled respondents to leave home and return if needed. The findings suggest that early residential independence reflects various factors, not all of which are in young people’s control, and some of which may hinder the longer term sustainability of their living arrangements.     

Data envelopment analysis 1978–2010: A citation-based literature survey

This study surveys the data envelopment analysis (DEA) literature by applying a citation-based approach. The main goals are to find a set of papers playing the central role in DEA development and to discover the latest active DEA subareas. A directional network is constructed based on citation relationships among academic papers. After assigning an importance index to each link in the citation network, main DEA development paths emerge. We examine various types of main paths, including local main path, global main path, and multiple main paths. The analysis result suggests, as expected, that Charnes et al. (1978) [Charnes A, Cooper WW, Rhodes E. Measuring the efficiency of decision making units. European Journal of Operational Research 1978; 2(6): 429–444] is the most influential DEA paper. The five most active DEA subareas in recent years are identified; among them the “two-stage contextual factor evaluation framework” is relatively more active. Aside from the main path analysis, we summarize basic statistics on DEA journals and researchers. A growth curve analysis hints that the DEA literature’s size will eventually grow to at least double the size of the existing literature.     

Symbolic cumulant calculations for frequency domain time series

With time series data, there is often the issue of finding accurate approximations for the variance of such quantities as the sample autocovariance function or spectral estimate. Smith and Field (J. Time. Ser. Anal 14: 381–395, 1993) proposed a variance estimate motivated by resampling in the frequency domain. In this paper we present some results on the cumulants of this and other frequency domain estimates obtained via symbolic computation. The statistics of interest are linear combinations of products of discrete Fourier transforms. We describe an operator which calculates the joint cumulants of such statistics, and use the operator to deepen our understanding of the behaviour of the resampling based variance estimate. The operator acts as a filter for a general purpose operator described in Andrews and Stafford (J.R. Statist. Soc. B55, 613–627).     

Metacognitions in Problem Gambling

Problem gambling is heterogeneous in nature, ranging in severity from occasional but problematic gambling episodes, to extreme, impulsive and pervasive gambling behaviour. Problem gambling may be accompanied by a sense of impaired control and can give rise to financial, interpersonal, legal and vocational costs for the sufferer, their families and society. This study investigated the relationship among metacognitions, anxiety, depression and gambling in a sample of problem gamblers. A total of 91 individuals attending gambling treatment services completed a battery of self-report instruments that consisted of the Metacognitions Questionnaire 30 (MCQ-30), the Hospital Anxiety and Depression Scale (HADS) and the South Oaks Gambling Scale (SOGS). Correlation analyses showed that anxiety, depression and metacognitions were positively and significantly correlated with both gambling consequences and behaviour. Hierarchical regression analyses indicated that two metacognitive constructs (negative beliefs about thoughts concerning uncontrollability and danger and beliefs about the need to control thoughts) predicted gambling behaviour independently of anxiety and depression. These findings are consistent with the hypothesis that metacognitions play a role in problem gambling.     

Exegetical Explorations: Parsons’ Theoretical Faith and Hope in Structural Functional Analysis

This article discusses Talcott Parsons scientific world-view and how his theory gave expression to his more-than-merely theoretical reliance upon insights he gleaned from Whitehead and Weber. He developed “social systems theory” not only with a structural-functional and evolutionary understanding of social action but also saw science, in these terms as well. The article seeks to trace his theory’s reliance upon the system concept which gave his work a persistent focus throughout his scholarly career.     

The Teaching of Hypnosis: Outline and Method

Abstract

In the past several years there has been a significant increase in the number of training programs in clinical hypnosis. There appears to be little information available regarding the actual method and content of such coursework. The authors gave a number of professionals and paraprofessionals a training program that included lectures, clinical inductions, and an opportunity for limited use of these methods in a supervised setting. The methods used were presented in a step-by-step fashion, drawing upon not only the authors' experience and expertise, but also requiring the active participation of those learning these clinical methods. In all, there were ten sessions with some required reading outside of the class time. Typical problems of resistance, problem solving, and various perspectives were discussed and employed.     

Nonlinear voxel-based modelling of the haemodynamic response in fMRI

A common assumption for data analysis in functional magnetic resonance imaging is that the response signal can be modelled as the convolution of a haemodynamic response (HDR) kernel with a stimulus reference function. Early approaches modelled spatially constant HDR kernels, but more recently spatially varying models have been proposed. However, convolution limits the flexibility of these models and their ability to capture spatial variation. Here, a range of (nonlinear) parametric curves are fitted by least squares minimisation directly to individual voxel HDRs (i.e., without using convolution). A ‘constrained gamma curve’ is proposed as an efficient form for fitting the HDR at each individual voxel. This curve allows for spatial variation in the delay of the HDR, but places a global constraint on the temporal spread. The approach of directly fitting individual parameters of HDR shape is demonstrated to lead to an improved fit of response estimates.