Towards Diversity in Recommendations Using Social Networks

While there has been a lot of research towards improving the accuracy of recommender systems, the resulting systems have tended to become increasingly narrow in suggestion variety. An emerging trend in recommendation systems is to actively seek out diversity in recommendations, where the aim is to provide unexpected, varied, and serendipitous recommendations to the user. Our main contribution in this paper is a new approach to diversity in recommendations called "Social Diversity," a technique that uses social network information to diversify recommendation results. Social Diversity utilizes social networks in recommender systems to leverage the diverse underlying preferences of different user communities to introduce diversity into recommendations. This form of diversification ensures that users in different social networks (who may not collaborate in real life, since they are in a different network) share information, helping to prevent siloization of knowledge and recommendations. We describe our approach and show its feasibility in providing diverse recommendations for the MovieLens dataset

Cross-taxon congruence and environmental conditions

<p>Abstract</p> <p>Background</p> <p>Diversity patterns of different taxa typically covary in space, a phenomenon called cross-taxon congruence. This pattern has been explained by the effect of one taxon diversity on taxon diversity, shared biogeographic histories of different taxa, and/or common responses to environmental conditions. A meta-analysis of the association between environment and diversity patterns found that in 83 out of 85 studies, more than 60% of the spatial variability in species richness was related to variables representing energy, water or their interaction. The role of the environment determining taxa diversity patterns leads us to hypothesize that this would explain the observed cross-taxon congruence. However, recent analyses reported the persistence of cross-taxon congruence when environmental effect was statistically removed. Here we evaluate this hypothesis, analyzing the cross-taxon congruence between birds and mammals in the Brazilian Cerrado, and assess the environmental role on the spatial covariation in diversity patterns.</p> <p>Results</p> <p>We found a positive association between avian and mammal richness and a positive latitudinal trend for both groups in the Brazilian Cerrado. Regression analyses indicated an effect of latitude, PET, and mean temperature over both biological groups. In addition, we show that NDVI was only associated with avian diversity; while the annual relative humidity, was only correlated with mammal diversity. We determined the environmental effects on diversity in a path analysis that accounted for 73% and 76% of the spatial variation in avian and mammal richness. However, an association between avian and mammal diversity remains significant. Indeed, the importance of this link between bird and mammal diversity was also supported by a significant association between birds and mammal spatial autoregressive model residuals.</p> <p>Conclusion</p> <p>Our study corroborates the main role of environmental conditions on diversity patterns, but suggests that other important mechanisms, which have not been properly evaluated, are involved in the observed cross-taxon congruence. The approaches introduced here indicate that the prevalence of a significant association among taxa, after considering the environmental determinant, could indicate both the need to incorporate additional processes (e.g. biogeographic and evolutionary history or trophic interactions) and/or the existence of a shared trend in detection biases among taxa and regions.</p

Deconstructing Transnationalism: Conceptualizing Metanationalism as a Putative Model of Evolving Jurisprudence

This Article builds upon Philip C. Jessup\u27s revolutionary scholarship to pave new pathways for interdisciplinary research and expand the normative constitutional framework of universal human problems. To that end, this Article ties American constitutional theory to the new era of international globalization and provides context that facilitates the discussion of racial and ethnic diversity in education from a domestic and international perspective. By arguing for compelling treatment of diversity in elementary and secondary learning institutions, this Article introduces a new theory of constitutional interpretation vis-&-vis international law. This theory, called metanationalism, rejects Harold Koh\u27s theory of transnationalism and demonstrates that nationalism and transnationalism are not two mutually exclusive concepts at opposite ends of a linear spectrum of constitutional theory. Contrary to Koh\u27s postulate, metanationalism conceptualizes these two theories as components in a multidimensional paradigm where such theories exist to broaden and enrich legal analysis. Applying metanationalism, this Article argues that existing literature overlooks diversity\u27s role in the global education-rights movement and focuses on India as a case study. Lastly, this Article analyzes a recent trend in U.S. constitutional law to advocate revisiting the current equal protection landscape

Adapting Recommendation Diversity to Openness to Experience : A Study of Human Behaviour

Postprin

Haplotype Network Branch Diversity, a New Metric Combining Genetic and Topological Diversity to Compare the Complexity of Haplotype Networks

A common way of illustrating phylogeographic results is through the use of haplotype networks. While these networks help to visualize relationships between individuals, populations, and species, evolutionary studies often only quantitatively analyze genetic diversity among haplotypes and ignore other network properties. Here, we present a new metric, haplotype network branch diversity (HBd), as an easy way to quantifiably compare haplotype network complexity. Our metric builds off the logic of combining genetic and topological diversity to estimate complexity previously used by the published metric haplotype network diversity (HNd). However, unlike HNd which uses a combination of network features to produce complexity values that cannot be defined in probabilistic terms, thereby obscuring the values’ implication for a sampled population, HBd uses frequencies of haplotype classes to incorporate topological information of networks, keeping the focus on the population and providing easy-to-interpret probabilistic values for randomly sampled individuals. The goal of this study is to introduce this more intuitive metric and provide an R script that allows researchers to calculate diversity and complexity indices from haplotype networks. A group of datasets, generated manually (model dataset) and based on published data (empirical dataset), were used to illustrate the behavior of HBd and both of its terms, haplotype diversity, and a new index called branch diversity. Results followed a predicted trend in both model and empirical datasets, from low metric values in simple networks to high values in complex networks. In short, the new combined metric joins genetic and topological diversity of haplotype networks, into a single complexity value. Based on our analysis, we recommend the use of HBd, as it makes direct comparisons of network complexity straightforward and provides probabilistic values that can readily discriminate situations that are difficult to resolve with available metrics

Highlighting tensions in recruitment and selection research and practice

In this article we highlight five tensions that exist in recruitment and selection (R&S) research and practice today and that are centered around the 'efficiency press' and so called 'research-practice' gap. Identified tensions are desires for (1) innovation and efficiency, (2) customization and consistency, (3) transparency and effectiveness, (4) wide-reach and coherence, and (5) diversity and standardization. Each tension is illustrated with findings from the five studies of this Special Issue that were presented at the third meeting of the European Network of Selection Researchers (August 2014), and supplemented with empirical data on the research-practice gap in R&S (period 2009-2013). We consider how we might move forward in addressing the 'efficiency press' in research as well as managing these tensions in practice

Convergence and Diversity in International and Comparative Industrial Relations

[Excerpt] In this essay, we reexamine a critical paradox in international and comparative industrial relations, a paradox that already decades ago demonstrated its ability to intrigue scholarly curiosity (Galenson, 1952,1963; Kerr et al, 1960). As we see it, convergence along a number of important dimensions, such as labor law and organizational and bargaining structure, is occurring simultaneously with widespread cross-national and local divergence, or diversity, in industrial relations practices and outcomes. Along with economic and political interdependence and with intensifications of market competition, convergence and diversity both appear to be product of an increasing spread of markets and ideas sometimes referred to as globalization. In employing this term, we intend to make the point that the conduct of global business is no longer confined to the sort of international trading and related activities that have been carried on for centuries already. In the modern era, the production and exchange of both goods and services occur increasingly on a global scale (Reich, 1991). At this level, as capital mobility expands and trade agreements proliferate (NAFTA, CATT, the single European market), national governments find it increasingly difficult to regulate markets. This globalization of markets, we suggest, is the dominant force driving change (whether toward convergence or diversity) in the contemporary period. Our observations are especially applicable to the advanced industrial countries of the Organization for Economic Cooperation and Development (OECD), the primary focus of this paper, although the trends identified here probably also hold to some extent for newly industrialized countries and less developed societies as well