The Analysis of Designed Experiments and Longitudinal Data by Using Smoothing Splines

In designed experiments and in particular longitudinal studies, the aim may be to assess the effect of a quantitative variable such as time on treatment effects. Modelling treatment effects can be complex in the presence of other sources of variation. Three examples are presented to illustrate an approach to analysis in such cases. The first example is a longitudinal experiment on the growth of cows under a factorial treatment structure where serial correlation and variance heterogeneity complicate the analysis. The second example involves the calibration of optical density and the concentration of a protein DNase in the presence of sampling variation and variance heterogeneity. The final example is a multienvironment agricultural field experiment in which a yield–seeding rate relationship is required for several varieties of lupins. Spatial variation within environments, heterogeneity between environments and variation between varieties all need to be incorporated in the analysis. In this paper, the cubic smoothing spline is used in conjunction with fixed and random effects, random coefficients and variance modelling to provide simultaneous modelling of trends and covariance structure. The key result that allows coherent and flexible empirical model building in complex situations is the linear mixed model representation of the cubic smoothing spline. An extension is proposed in which trend is partitioned into smooth and non-smooth components. Estimation and inference, the analysis of the three examples and a discussion of extensions and unresolved issues are also presented.     

‘I Don't Just Want to Do It for Myself’: Diverse Pespectives on Being Successful at University by Social Work Students Who Speak English as an Additional Language

This article gives attention to furthering understandings about what being successful at university means to social work students, focusing on the perspectives of students who speak English as an additional language (EAL). It departs from approaches in the literature that focus on problematic aspects of teaching and learning. The article is informed by data from a small-scale focus group study of nine students from an undergraduate and a postgraduate social work programme in a South Australian university. Drawing on a methodological approach known as ‘Appreciative Inquiry’, students were asked how they conceptualise, experience and imagine success at university. The study found that students’ understandings of success are inextricably intertwined with their individual, family and community aspirations. These findings are discussed in the light of current dominant assumptions about the notion of success and possible directions for future research and implications for social work education.     

Promoting small business in Northern Ireland

During the last 10 years, Northern Ireland has suffered the same economic fate as the rest of the United Kingdom—a severe decline in its manufacturing base, and with this a substantial growth in unemployment to unacceptable levels. In response, a strategy for regeneration has been constructed. The main thrust of this strategy has been three-fold:

1. (1) To seek Inward Investment.

2. (2) To stimulate New Firms.

3. (3) To encourage Existing Firms to grow.

The strategy has involved a wide range of schemes of advice and assistance, managed through the Department of Economic Development, the Industrial Development Board (IDB), the Local Enterprise Development Unit (LEDU), as well as local enterprise organizations.

However, whilst many of the problems encountered, for which various schemes have been devised, can be seen replicated elsewhere in the United Kingdom, the basic problems in Norther Ireland are different in character.     

The stranger as seer or voyeur: A dilemma of the peep-show theory of knowledge

The belief that ‘the stranger’ (outsider, disinterested third party) sees things more clearly, i.e. is more “objective,” is seen to be a corner-stone of folk wisdom; underlying Western judicial thought and concepts of objectivity in the social sciences. The author raises the dilemma that both positivistic and humanistic sociologists accept this belief—suggesting 1) that it is a residue of positivism and a quest for certain knowledge, or 2) the possibility that ‘the stranger’ does gain deeper insight into group life than members. The paper examines the concept of the stranger, considering the aura of charisma that seems to have been attached to it in ordinary discourse as well as within the sociological dialogue. Two types of strangers are described: outsiders and enemies within. Finally, an attempt is made to examine the testimony of prominant strangers as they describe their marginal status and speculate on the ways that status has made them unusually perceptive observers of social phenomena.     

The development and field testing of a vocational education evaluation model

Reported is the development and field testing of an evaluation model used to evaluate the vocational education programs at the Metropolitan Community Colleges (MCC) of Kansas City, Missouri which can be implemented on vocational programs at other institutions. The model evaluated a vocational program on the following six criteria: (1) program's relationship to job market profile; (2) program's level of community support; (3) program's success in meeting vocational aspirations of clientele; (4) program's success in terms of student performance; (5) program 's cost-effectiveness; and (6) program 's success in reaching the handicapped and disadvantaged. The evaluation model provides a strategy and a set of procedures for assessing the quality of existing vocational education programs of study at any post-secondary institution. The model can be easily and inexpensively implemented, thus providing a data base which is useful for administrative planning and decision making.     

The need for a corporate strategy on risk management and risk transfer

Accidents happen to companies every day, but only some are catastrophic. Minimising them is more than just insurance; the correct strategy is risk management and involves the development of a Disaster Plan and a Crisis Management Plan. Sue Braithwaite explores the setting-up and organisation of such plans which involve, among other things, the interrelationship and co-ordination of risks, responsibilities, back-up contact, support and communications, testing and insurance. She insists that a company's long-term viability must include a developed strategy on the management of risk, loss prevention and control and damage containment.     

Prediction in linear mixed models

Following estimation of effects from a linear mixed model, it is often useful to form predicted values for certain factor/variate combinations. The process has been well defined for linear models, but the introduction of random effects into the model means that a decision has to be made about the inclusion or exclusion of random model terms from the predictions. This paper discusses the interpretation of predictions formed including or excluding random terms. Four datasets are used to illustrate circumstances where different prediction strategies may be appropriate: in an orthogonal design, an unbalanced nested structure, a model with cubic smoothing spline terms and for kriging after spatial analysis. The examples also show the need for different weighting schemes that recognize nesting and aliasing during prediction, and the necessity of being able to detect inestimable predictions.