A model for collaboration networks giving rise to a power-law distribution with an exponential cutoff

Recently several authors have proposed stochastic evolutionary models for the growth of complex networks that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the “rich get richer” phenomenon. Despite the generality of the proposed stochastic models, there are still some unexplained phenomena, which may arise due to the limited size of networks such as protein, e-mail, actor and collaboration networks. Such networks may in fact exhibit an exponential cutoff in the power-law scaling, although this cutoff may only be observable in the tail of the distribution for extremely large networks. We propose a modification of the basic stochastic evolutionary model, so that after a node is chosen preferentially, say according to the number of its inlinks, there is a small probability that this node will become inactive. We show that as a result of this modification, by viewing the stochastic process in terms of an urn transfer model, we obtain a power-law distribution with an exponential cutoff. Unlike many other models, the current model can capture instances where the exponent of the distribution is less than or equal to two. As a proof of concept, we demonstrate the consistency of our model empirically by analysing the Mathematical Research collaboration network, the distribution of which has been shown to be compatible with a power law with an exponential cutoff.     

Self-advocates have the last say on friendship

This study reports the friendship experiences and aspirations of adults with intellectual disabilities. The findings of a larger study were reviewed by an expert group of self-advocates with intellectual disability. The expert group confirmed some of the interpretation of the original data and expanded on issues. Friendship is established as an issue of concern among adults with intellectual disability. Consequently, policy-makers and service providers need to be intentional about providing support for friendships. Participants asserted a positive self-identity of being a person with intellectual disability and how this could be a basis for friendship. Also, people with intellectual disability demonstrated how they should be considered experts in their own life experience and how they can be effectively included in the formulation, implementation, analysis and review of research.     

Regularization and variable selection via the elastic net

Summary.  We propose the elastic net, a new regularization and variable selection method. Real world data and a simulation study show that the elastic net often outperforms the lasso, while enjoying a similar sparsity of representation. In addition, the elastic net encourages a grouping effect, where strongly correlated predictors tend to be in or out of the model together. The elastic net is particularly useful when the number of predictors ( p ) is much bigger than the number of observations ( n ). By contrast, the lasso is not a very satisfactory variable selection method in the p ≫ n case. An algorithm called LARS-EN is proposed for computing elastic net regularization paths efficiently, much like algorithm LARS does for the lasso.     

The photo‐survey research method: capturing life in the city

Recent promotion of city centre living within UK policy has led to a commensurate interest in city centre conditions and the opinions and experiences of the people who live there. An apposite, straightforward method to capture city centre residents' experiences and views is described in this article. We successfully combined a novel, under‐utilized visual technique (self‐directed photography) with qualitative methods (log‐sheets and interviews) in the form of a ‘photo‐survey’. A background to visual methodologies is presented in this article, alongside a critique of using the photo‐survey with 84 city centre residents to investigate environmental conditions and perceptions within three of the UK's major cities. The method provided a rich, detailed set of data, but also brought a number of noticeable benefits to the data collection process. The photo‐survey not only effectively captured and documented life in the city but also acted as an ‘agent for change’, evoking thoughts and feelings which ultimately encouraged participants to reflect on their existing perceptions and urban experiences. The study also raises some important considerations for future work undertaken with this method and with using photographs as a set of data, and proposes techniques for minimising potential problems.     

Urban Aboriginal use of fringe financial institutions: Survey evidence from Prince George, British Columbia

This paper analyses the use of fringe financial institutions (FFIs), such as payday loan and check cashing providers, by urban Aboriginal people based on a survey undertaken in Prince George, British Columbia. We found that 60% of FFIs’ clients surveyed self-identified as Aboriginal. Their characteristics, compared to the non-Aboriginal FFI clients, included having lower average incomes, lower levels of education, more likely to be female, a higher incidence of being unemployed, higher levels of financial exclusion, and less satisfaction with the service provided by FFIs. We find that government policy towards regulating the FFI industry is inadequate for meeting the basic financial needs of urban Aboriginal people.     

DEFINING MOMENTS: THE TENSION BETWEEN RICHNESS AND REACH

The defining moments of traditional spatially based higher education are made up of fixed and fluid experiences. These 'moments' are now creaking as funding per student falls and the romanticized ideal of an education detached from 'real' life falters under the weight of highly variable student experiences. Distance learning in all its guises has always been regarded as inferior by those embedded in the traditional system. However more and more students demand something different from costly campus-based education. It is time for a more open discussion about the tensions between richness and reach and the role that new facilities like the Internet could play in reaching more students without wallowing in the nostalgia that often accompanies such debates.     

Working with the Experts: collaborative research with people with an intellectual disability

This paper reports on part of a wider study concerned with the collaborative efforts of an inquirer and six people with an intellectual disability, to develop a grounded theory explaining the processes by which these informants manage the relationships within their personal communities. The study was conducted through a series of in-depth interviews with each informant; a process characterised by information sharing, tentative theory development and elaboration, and informants' checking the accuracy of the emerging theory. This inductive approach allowed not only an insight into the lives of each informant, but recognised the informants' expertise in matters concerning their own lives and thus facilitated the emergence of theoretical elements of relevance to the informants themselves. The focus of the paper is on the collaborative or partnership approach adopted. The outcomes of the research partnership are detailed and implications drawn for the role of research in the lifestyles of people with an intellectual disability.     

Developing creative solutions to the problems of children and their families: communicative reason and the use of forum theatre

The paper represents a further development of work previously reported in this journal by Spratt & Houston (1999) and Spratt et al. (2000) . The authors have sought to develop ways of understanding current social work with children and families in line with the critical theory of Jurgen Habermas. This analysis has been complemented by an adoption of the methodology of the radical dramatist, Augusto Boal. In synthesizing Habermas's analysis of communicative discourses with the consciousness raising methodology of Boal, the authors have already demonstrated the effectiveness of this hybrid in problem‐solving exercises with social workers. The present paper reports on an application of this developing theory to practice, utilizing the centrepiece of Boal's method, forum theatre. A forum theatre project, concerned with the issue of bullying, is described and evaluated. It is argued that the project provides an exemplar of an innovative, democratizing and effective methodology that might profitably be utilized in social work with children and families. Finally, suggestions are made as to how these ideas could be developed in practice.