Longitudinal measurement models in evaluation research: Examining stability and change

This article provides an introduction to the use of Confirmatory Factor Analysis to test measurement invariance and stability in longitudinal research. The approach is illustrated through examples representing: (a) one construct, two measurement waves; (b) one construct, three waves; (c) two constructs, two waves; and (d) comparison of treatment and control groups in pre-post designs. Basic issues in establishing measurement invariance over time, across treatment groups, and within measurement waves are discussed. Estimates of the stability coefficients that are corrected for measurement error and method variance associated with each specific measured variable are provided. Establishing measurement invariance is a critical requirement for making inferences about treatment effects and changes in constructs over time.     

Robust scale estimation in the error-components model using the empirical characteristic function

Robust estimators of the scale parameters in the error-components model are described. The new estimators are based on the empirical characteristic functions of appropriate sets of residuals and are affine equivariant, consistent and asymptotically normal. The robustness of the new estimators is investigated via influence-function calculations. The results of Monte Carlo experiments and an example based on real data illustrate the usefulness of the estimators.     

Reevaluation of task-centered social work practice

In a brief period of time, the “task-centered” approach to social work practice has become a major treatment modality, offering the clinician a degree of specificity and clarity that is often missing in more traditional practice. This paper reassesses the indications and contraindications for this model, contrasting it with other treatment approaches which also utilize the technical variables of brevity, time limits, and task assignment. The diagnostic criteria for the utilization of this approach are discussed in detail, with special emphasis on its applicability to the severely disturbed client.     

Workplace discrimination and disfigurement: the national EEOC ADA research project

Using the Integrated Mission System of the Equal Employment Opportunity Commission, the employment discrimination experience of Americans with disfigurement is documented. Key dimensions of workplace discrimination involving Americans with disfigurement and persons with missing limbs are compared and contrasted. Specifically, the researchers examine demographic characteristics of Charging Parties; the industry designation, location and size of Respondents/employers; the discrimination Issue (i.e., type of adverse action) alleged to occur; and the legal outcome or Resolution of these allegations. Charging Parties with disfigurement who are female or between 30 and 39 years of age are more likely to encounter employment discrimination than their counterparts with missing limbs. Harassment and Non-wage Benefits are the Issues that emerge in higher proportion. Allegations derived from persons with disfigurement are more common in among mid-size employers, those located in the South, or those in Retail or Service industries. Following investigation, allegations derived from persons with disfigurement are less likely to have Merit Resolutions than those brought by Charging Parties with missing limbs.     

The meshing of youth development and community building

Practitioners, policymakers, residents, workers, researchers, and even funders have an opportunity to merge their many practices into a more comprehensive and focused approach to change communities substantially. People are affiliated with a number of communities, and not just those with geographical definitions. There are communities based on gender, sexual orientation, physical ability, race, ethnicity, and institutions such as family and school. Building the bridges between youth development and community building and merging their principles and practices will create a force of change. This chapter lays the foundation for meshing the worlds of youth development and community building to make powerful connections that will be important to the community of youth and bring them into wider circles and forces that ultimately will be important to the adult community as well.     

The 1991 Cholera Epidemic in Peru: Not a Case of Precaution Gone Awry

The precautionary principle calls on decisionmakers to take preventive action in light of evidence indicating that there is a potential for harm to public health and the environment, even though the nature and magnitude of harm are not fully understood scientifically. Critics of the precautionary principle frequently argue that unbridled application of the principle leads to unintended damage to health and ecosystems (risk tradeoffs) and that precautious decision making leaves us vulnerable to "false-positive" risks that divert resources away from "real risks." The 1991 cholera epidemic in Peru is often cited as an example of these pitfalls of the precautionary principle. It has been mistakenly argued that application of the precautionary principle caused decisionmakers to stop chlorinating the water supply due to the risks of disinfection byproducts (DBPs), resulting in the epidemic. Through analyses of investigations conducted in the cities of Iquitos and Trujillo, Peru, literature review, and interviews with leading Peruvian infectious disease researchers, we determined that the epidemic was caused by a much more complex set of circumstances, including poor sanitation conditions, poor separation of water and waste streams, and inadequate water treatment and distribution systems. The evidence indicates that no decision was made to stop chlorinating on the basis of DBP concerns and that concerns raised about DBPs masked more important factors limiting expansion of chlorination. In fact, outside of Peru's capital Lima, chlorination of drinking water supplies at the time of the epidemic was limited at best. We conclude that the Peruvian cholera epidemic was not caused by a failure of precaution but rather by an inadequate public health infrastructure unable to control a known risk: that of microbial contamination of water supplies.