Diagnosing Global Case Influence on MAR Versus MNAR Model Comparisons

When missingness is suspected to be not at random (MNAR) in longitudinal studies, researchers sometimes compare the fit of a target model that assumes missingness at random (here termed a MAR model) and a model that accommodates a hypothesized MNAR missingness mechanism (here termed a MNAR model). It is well known that such comparisons are only interpretable conditional on the validity of the chosen MNAR model’s assumptions about the missingness mechanism. For that reason, researchers often perform a sensitivity analysis comparing the MAR model to not one, but several, plausible alternative MNAR models. In the social sciences, it is not widely known that such model comparisons can be particularly sensitive to case influence, such that conclusions drawn could depend on a single case. This article describes two convenient diagnostics suited for detecting case influence on MAR–MNAR model comparisons. Both diagnostics require much less computational burden than global influence diagnostics that have been used in other disciplines for MNAR sensitivity analyses. We illustrate the interpretation and implementation of these diagnostics with simulated and empirical latent growth modeling examples. It is hoped that this article increases awareness of the potential for case influence on MAR–MNAR model comparisons and how it could be detected in longitudinal social science applications.     

Software review

STATISTICA 5.0. StatSoft, 2325 East 13th Street, Tulsa, OK 74104, (918) 583–4149. $995 retail, academic site license—$2,000 for 10 copies. Requirements: 386 or better, 4 Meg RAM, Microsoft Windows 3.1 or 95.     

Validation of the child sex abuse attitude scale through confirmatory factor analysis

A validation study was conducted on the Child Sex Abuse Attitude Scale (CSAAS) using confirmatory factor analysis (CFA) to examine factor structure. The CSAAS was developed based on Festinger's (1957) theory of attitude development resulting in a 4‐factor first‐order structure (cognition, value, affect, and behavior) and a single‐factor 2nd‐order structure (attitude). A sample of 215 school psychologists, members of the National Association of School Psychologists, responded to the CSAAS survey. CFA results supported the hypothesized factor structure of the CSAAS, thus indicating the plausibility of a 4‐factor 1st‐order and a single‐factor higher order structure of the CSAAS.     

Explaining Method Effects Associated With Negatively Worded Items in Trait and State Global and Domain-Specific Self-Esteem Scales

Several investigators have interpreted method effects associated with negatively worded items in a substantive way. This research extends those studies in different ways: (a) it establishes the presence of methods effects in further populations and particular scales, and (b) it examines the possible relations between a method factor associated with negatively worded items and several covariates. Two samples were assessed: 592 high school students from Valencia (Spain), and 285 batterers from the same city. The self-esteem scales used were Rosenberg's Self-Esteem Scale, the State Self-Esteem Scale, and Self-Esteem 17. Anxiety was also assessed with the State-Trait Anxiety Inventory, and gender and educational level were taken into account. The models were conducted using a multiple indicators and multiple causes (MIMIC) model framework. The evidence in this research pointed out that method effects were present across the different measures of self-esteem. Moreover, a significant and negative effect of anxiety on method effects was present across scales and samples, whereas no effects of age or educational level where found.     

Fitting Nonlinear Latent Growth Curve Models With Individually Varying Time Points

Individual growth trajectories of psychological phenomena are often theorized to be nonlinear. Additionally, individuals’ measurement schedules might be unique. In a structural equation framework, latent growth curve model (LGM) applications typically have either (a) modeled nonlinearity assuming some degree of balance in measurement schedules, or (b) accommodated truly individually varying time points, assuming linear growth. This article describes how to fit 4 popular nonlinear LGMs (polynomial, shape-factor, piecewise, and structured latent curve) with truly individually varying time points, via a definition variable approach. The extension is straightforward for certain nonlinear LGMs (e.g., polynomial and structured latent curve) but in the case of shape-factor LGMs requires a reexpression of the model, and in the case of piecewise LGMs requires introduction of a general framework for imparting piecewise structure, along with tools for its automation. All 4 nonlinear LGMs with individually varying time scores are demonstrated using an empirical example on infant weight, and software syntax is provided. The discussion highlights some advantages of modeling nonlinear growth within structural equation versus multilevel frameworks, when time scores individually vary.     

“整合连贯型”数学教育人才培养质量体系构想

随着我国高等师范教育的改革和发展,催生了教师教育方向大学生人才培养“整合连贯型”的新模式.数学专业教师教育方向大学生人才培养如何适应社会和个人发展的需要,并保障人才培养的质量,就成为一个必须思考和迫切解决的问题.根据数学专业教师教育方向的专业特点,结合长期教学实践调研,提出了“整合连贯型”模式下数学专业教师教育方向大学生人才培养质量体系的框架构想,以期提高数学专业教师教育方向大学生人才培养的质量.     

微信在大学英语教学中的应用

微信作为新的交流方式给网络化外语教育带来了新机遇。从微信的功能出发,阐述其在大学英语教学中的优势和特点,探讨在大学英语教学中的设计与应用模式,从而充分利用微信有效地促进大学英语教学。     

New lamps for old: financialised governance of cities and clean energy

ABSTRACT

Using a six-year case study of Glasgow’s Sustainable City business model, this paper examines interactions between financialised governance of cities and clean energy strategies. Research on the role of cities in developing clean energy has paid limited attention to the interaction with financialised governance of infrastructure, which makes the implementation of plans largely dependent on private investment. A conceptual approach combining economic sociology of actor networks and urban political economy is used to analyse the career of the business model designed to transform old infrastructures into new clean energy assets. The analysis focuses on interactions between city council, public bodies and electricity distribution network business. Climate policies are creating uncertainties for energy businesses over revenues from ageing networks, suggesting scope for alliance with local governments. Making new liquid assets for clean energy from old infrastructure is however shown to be a process marked by instability and reversals. In conclusion, it is argued that concepts from actor-network theory and urban political economy used together reveal the hidden contingencies of financialisation in particular socio-technical interactions, and their materiality in the context of climate change.     

Ebooks in Academic Libraries

Abstract

The number of ebooks continues to grow in academic libraries. Ebooks have many advantages that make them attractive as a library resource. However, ebooks also have restrictions. These include use and sharing restrictions, license restrictions, and technological barriers. Some students also prefer print books for specific tasks. The following articles examine many aspects of ebooks in academic libraries, including student preference, overall ebook use, and the advantages and disadvantages of various ebook acquisition models.