Random effects regression mixtures for analyzing infant habituation

Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.     

Disability in Somaliland

Civil war lasting into the 1990s destroyed much of Somalia's economic, political and social structures, and conflict still continues in the southern areas of the country. In 1991, the northwest region declared itself the Independent Republic of Somaliland, established a government in Hargeisa and is struggling to rebuild an infrastructure. It is one of the poorest countries in the world, ranking high on the UN hunger index, and is the third most heavily land-mined country. One of the most disadvantaged groups of people are the disabled, although there is little general information about numbers and kinds of disability, and few social and medical services. This article presents some limited information about the extent of the nature of disability, and local efforts to improve the lives of disabled children and adults. It reports projects funded by non-government organisations, and concentrates on a seminar held in early 2002 attended by a group of disabled people who made their voices heard.     

Accommodation issues in the work place for people with disabilities: a needs assessment in an educational setting

The passage in the USA of the Americans with Disabilities Act (ADA) has mandated the private sector to provide a sweeping variety of accommodations to individuals with disabilities. Objections to ADA focused on costs in an era of scarcity. These assumptions have been presented with insufficient information about the actual needs of individuals with disabilities. This study is a needs assessment of employees with disabilities at a major university setting. In-depth interviews were conducted with a small number of individuals who described their work situations and accommodations. Findings challenge prevailing assumptions. Costs are often not large, many accommodations are simple, and much depends on the match between a person's disability and job duties. Additionally, informational needs, psychological concerns and the existing social climate provide a more balanced picture of the lives of these employees.     

Small Town in Mass Society Revisited1

Abstract The case study of a small New York town that dramatized the thesis that the secular expansion of macro forces—urbanization, industrialization, bureaucratization—has permanently reduced the autonomy of all small communities is an example of a special type of discovery/persuasion strategy in the social sciences: the “opposition case study.” In contrast to the more rigorous “competitive test” or the atheoretical “negative case,” opposition case studies confront the dominant perspective with a qualitative illustration of a new theory in the context of a zero-sum game. When they are successful, opposition cases meet four criteria: the dominant view is immediately rendered obsolete; the origin of the new idea supports its plausibility; the new perspective is shown to be testable; and the new perspective quickly generates new lines of research. Small Town in Mass Society meets the first criterion, and may have been heuristic, but its probable origin in populist ideology undermines its testability.     

The Impact of Question and Respondent Characteristics on Comprehension and Mapping Difficulties

Behavior coding is one technique researchers use to detect problemsin survey questions, but it has been primarily explored as apractical tool rather than a source of insight into the theoreticalunderstanding of the cognitive processes by which respondentsanswer survey questions. The latter is the focus of the currentinvestigation. Using data from a large study in which face-to-faceinterviews were taped and extensive behavior coding was done,we tested whether sets of respondent behavior codes could beused to distinguish respondent difficulties with comprehensionof the question from difficulties associated with mapping ajudgment onto the response format provided, and whether characteristicsof the survey questions and respondents could be used to predictwhen and for whom such difficulties would occur. Sets of behaviorcodes were identified that reflected comprehension and mappingdifficulties, and these two types of difficulties were associatedwith different question and respondent characteristics. Thisevidence suggests that behavior coding shows promise as a toolfor researchers studying the cognitive processes involved inanswering survey questions.     

Goal Ambiguity and Organizational Performance in U.S. Federal Agencies

In spite of numerous observations that government organizationshave high levels of organizational goal ambiguity that exertmajor influences on their other characteristics, few researchershave measured goal ambiguity and tested these frequent assertions.In previous research, we developed measures of four dimensionsof goal ambiguity: mission comprehension ambiguity, directivegoal ambiguity, evaluative goal ambiguity, and priority goalambiguity. Confirming hypotheses developed from the literatureon public organizations, the latter three variables showed relationsto such organizational characteristics as organizational age,financial publicness (proportion of funding from governmentallocations), and regulatory status. This article reports asecond analytical step of examining the relations between thegoal ambiguity dimensions and indicators of organizational performancebased on responses to the 2000 National Partnership for ReinventingGovernment Survey of federal employees. The performance variablesincluded managerial effectiveness, customer service orientation,productivity, and work quality. Regression analyses with numerouscontrol variables found that directive, evaluative, and prioritygoal ambiguity related negatively to managerial effectiveness.All four performance indicators showed significant negativerelationships with evaluative goal ambiguity and directive goalambiguity. The results provide further evidence of the viabilityof the new measures of goal ambiguity, support theory-basedbut previously untested hypotheses, and further indicate thefeasibility and value of analyzing goal ambiguity of governmentorganizations.     

The Political Economy of Special Educational Needs in Britain

This article raises questions as to how far young people regarded as having special educational needs or disabilities are prepared for participation in the economy. It focuses on those aspects of the further education curriculum that emphasises skills, and the development of National Vocational Qualifications which emphasise competences. Those with special educational needs or disabilities are part of a larger group of young people to be 'managed' as a workforce if there is work, and all are urged that the way to find employment is by constant investment in the self by the acquisition of skills and competences. The article contends that those labelled as special will find more difficulty in collecting meaningful skills and competences, and those in charge of new accreditation systems have made it clear that few concessions will be offered to this group.