Evaluating the Contributions of Individual Variables to a Quadratic Form

Quadratic forms capture multivariate information in a single number, making them useful, for example, in hypothesis testing. When a quadratic form is large and hence interesting, it might be informative to partition the quadratic form into contributions of individual variables. In this paper it is argued that meaningful partitions can be formed, though the precise partition that is determined will depend on the criterion used to select it. An intuitively reasonable criterion is proposed and the partition to which it leads is determined. The partition is based on a transformation that maximises the sum of the correlations between individual variables and the variables to which they transform under a constraint. Properties of the partition, including optimality properties, are examined. The contributions of individual variables to a quadratic form are less clear‐cut when variables are collinear, and forming new variables through rotation can lead to greater transparency. The transformation is adapted so that it has an invariance property under such rotation, whereby the assessed contributions are unchanged for variables that the rotation does not affect directly. Application of the partition to Hotelling's one‐ and two‐sample test statistics, Mahalanobis distance and discriminant analysis is described and illustrated through examples. It is shown that bootstrap confidence intervals for the contributions of individual variables to a partition are readily obtained.     

Performance measurement in industrial R&D

Currently, the need for R&D performance measurements that are both practically useful and theoretically sound seems to be generally acknowledged; indeed, the rising cost of R&D, greater emphasis on value management and a trend towards decentralization are escalating the need for ways of evaluating the contribution of R&D to corporate performance. However, although recent research and writing on the subject shows that the challenge of developing such sound measurements has been taken up by many academics and organizations, it is also clear that there is no generally applicable approach.
In this review, we consider various approaches for measuring the performance in industrial R&D and identify their key characteristics. We also include a brief summary of the 'history' of performance measurement in R&D, which shows that although there are some new ways of looking at the issue there are many examples from the past that can contribute to our current thinking.
The approaches found in the literature and practice are very varied in their application, some being more suitable for the project level, others for the R&D department, and some for the development process or for the organization as a whole. Furthermore, the uses of the approaches tend to be different. For example, some approaches are intended to justify the continuation of investment in R&D to upper management, whilst others are more suited to support learning and self-correction by empowered R&D teams. In this paper these uses, or 'functions', of performance measurement and a taxonomy of typical subjects of measurement in R&D environments are explored.
Finally, we conclude the review with a discussion of some limitations of the growing literature on R&D performance measurement.     

Graphical displays for clarifying how allocation ratio affects total sample size for the two sample logrank test

For time‐to‐event data, the power of the two sample logrank test for the comparison of two treatment groups can be greatly influenced by the ratio of the number of patients in each of the treatment groups. Despite the possible loss of power, unequal allocations may be of interest due to a need to collect more data on one of the groups or to considerations related to the acceptability of the treatments to patients. Investigators pursuing such designs may be interested in the cost of the unbalanced design relative to a balanced design with respect to the total number of patients required for the study. We present graphical displays to illustrate the sample size adjustment factor, or ratio of the sample size required by an unequal allocation compared to the sample size required by a balanced allocation, for various survival rates, treatment hazards ratios, and sample size allocation ratios. These graphical displays conveniently summarize information in the literature and provide a useful tool for planning sample sizes for the two sample logrank test. Copyright © 2010 John Wiley & Sons, Ltd.     

Demand-side strategy and business models: Putting value creation for consumers center stage

Value creation for consumers, as the conditio sine qua non for value capture, is at the heart of demand-side strategy research and is a core element of almost any business model. In this paper, we discuss the unique ideas that demand-side strategy and business model research jointly contribute to the strategy literature, and we elaborate on the potential for cross-fertilization between both areas of study. We argue that both the demand-side perspective and the business model concept could jointly promote a better understanding of strategy-making by mutually relying on the distinctive insights from each stream; specifically, while research on demand-side strategy can help business model scholars gain a more robust and granular understanding of effective value propositions, business models can serve as a “bridging concept” that links the shared ideas of both areas of study to resource-based streams of strategy research.     

The Emotional and Psychological Experiences of Drag Performers: A Qualitative Study

To better understand psychological experiences of drag queens, the authors conducted interviews with 12 cisgender, gay male drag queens from a midsouth state. Participants were age 22 to 54 years (M = 34) and reported participating in drag for 2 to 33 years (M = 13). The authors used consensual qualitative analysis to identify five main themes: motivation, effects, protective factors, stressors, and involvement. Results indicate that participants in drag may benefit from social support, a creative outlet, and empowerment. Participants also reported experiences of discrimination, performance anxiety, and loss of friendships. We discuss implications for counseling lesbian, gay, bisexual, and transgender people who may perform in drag.     

Frontline managers' perceptions and justifications of behavioural conditionality

The debate on behavioural conditionality is characterised by abundant controversies. Frontline managers have a particularly important role in implementing these policies because their interpretation of the welfare policies regulates the frameworks of street-level bureaucrat's discretionary powers. A nationwide survey among frontline managers in the Norwegian Labour and Welfare Administration revealed that 86% of the managers expressed strong normative support towards welfare conditionality. With this as a backdrop, this paper develops a better understanding of managers' perceptions and justifications of the Norwegian type of behavioural conditionality. Analysis of focus group interview data showed that the managers adopted a broad definition of conditionality, meaning promotion of an overall (re)integration of the client into the society as opposed to the narrow definition focusing solely on labour market integration. Furthermore, the implementation of welfare conditionality primarily was perceived as mild and client sensitive. The managers mainly justified welfare conditionality in terms of care and paternalistic defences, arguing that requirement of work and activities are in the client's best interest, understood in terms of social democratic values.     

From Poverty Reduction to Mutual Interests? The Debate on Differentiation in EU Development Policy

Aid to middle‐income countries has become one of the most discussed issues among development researchers and in the current modernisation of the development policy of the European Union. This article argues that the question needs to be dealt with in the context of two interlinked challenges: (i) the need to reconceptualise dominant approaches to global poverty reduction beyond national income, and (ii) the growing range of global challenges and the strategically important role of middle‐income countries. For EU development policy, the implications are twofold: (i) a better‐co‐ordinated cross‐country division of labour, and (ii) a diversification of objectives towards a global rationale of development policy involving closer co‐ordination with other EU external policies.