1,720,976 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Analysing biological, chemical and geomorphological interactions in rivers using structural equation modelling
No full textEffective management of river ecosystems requires knowledge of the interrelationships between biological, chemical and geomorphological processes and patterns. This is a complex challenge, and there are significant gaps in our understanding of these interrelationships. For example, the response of biological communities to geomorphological changes in rivers is particularly poorly understood. These knowledge gaps are compounded by the lack of coherent biological, chemical and geomorphological datasets for many rivers, limiting the extent to which traditional data analysis and modelling techniques can be applied. Here we describe the application of a new technique, Structural Equation Modelling (SEM), to the investigation of biological, chemical and geomorphological data collected from rivers across England and Wales. The SEM approach is a multivariate statistical technique enabling simultaneous examination of direct and indirect relationships across a network of variables. Further, SEM allows a-priori conceptual or theoretical models to be tested against available data. For example, a- priori models can be developed in collaboration with river managers and then evaluated using SEM as part of participatory modelling projects. This is a significant departure from the solely exploratory analyses which characterise other multivariate techniques. Bayesian approaches can also be applied within the SEM framework, offering the opportunity to address challenges such as incomplete datasets and non-normal data distributions. Such challenges are common in the analysis of spatial patterns associated with riverine ecosystems. We took biological, chemical and geomorphological data collected by the Environment Agency for 700 sites in rivers across England and Wales, and created a single, coherent dataset suitable for SEM analyses. Biological data cover benthic macroinvertebrates, chemical data relate to a range of standard parameters ( e. g. BOD, dissolved oxygen and phosphate concentration), and geomorphological data cover factors such as river typology, substrate material and degree of physical modification. We developed a number of a-priori theoretical models based on existing understanding of river ecosystems. These models were able to explain correctly the variance and covariance shown by the datasets, proving to be a relevant representation of the processes involved. The models explained around 80% of the variance in indices describing benthic macroinvertebrate communities. Dissolved oxygen was of primary importance, but geomorphological factors, including river habitat type and degree of habitat degradation, also had significant explanatory power. The model produced new insights into the relative importance of chemical and geomorphological factors for river macroinvertebrate communities. The SEM technique proved powerful, for example able to deal with the co-correlations that are common in rivers due to multiple feedback mechanisms. In this paper we also examine how SEM could be used to guide data collection and support decision-making (DM) for river ecosystems. We highlight the benefits of a Bayesian approach to solving SEM, especially in the context of supporting DM. We demonstrate how both simple and more complex a-priori conceptual models can be used in SEM. We explore whether greater complexity, which may add credibility to a model, increases explanatory power compared to relatively simple models. We examine how subjective judgements that are inherent to the development of a-priori models, for example relating to the separation between individual habitat types, influence the outcomes and interpretations of SEM analyses. Our experience highlights the importance of close collaboration with potential users throughout each step of the SEM framework, and we examine how this collaboration might be put into practice
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Structural equation modelling : a novel statistical framework for exploring the spatial distribution of benthic macroinvertebrates in riverine ecosystems
No full textBenthic macroinvertebrates have been used widely as bioindicators to assess the condition of riverine ecosystems. However, understanding and modelling the spatial distribution of benthic macroinvertebrates within these ecosystems remain significant challenges for research and management. Statistical analyses of multivariate data sets offer opportunities to explore the ecological systems controlling the distribution of biota. This article reports a novel statistical analysis of a national-scale data set from England and Wales using the structural equation modelling (SEM) framework. Relationships between water quality, physical habitat structure and indices reflecting benthic macroinvertebrate community structure were analysed using SEM. On the basis of data from 219 monitoring sites, structural equation models were built. These models explained 87% of the spatial variation in the average score per taxon index and 76% of the spatial variation in the Lotic Invertebrate Index for Flow Evaluation. Significant direct and indirect effects on these indices were exerted by water quality variables, particularly the concentrations of dissolved oxygen, biochemical oxygen demand and orthophosphate. Independent of water quality conditions, both biotic indices were directly affected by variables describing the structure and the degradation of physical habitat. The strengths of the SEM framework include (i) direct evaluation of a priori models against observed data, thereby supporting confirmatory analysis of theoretical models of ecological systems; (ii) specification of latent variables representing unmeasured constructs; and (iii) simultaneous assessment of multiple direct and indirect paths between variables within a model. These strengths define a framework with the potential to be applied widely in the development and testing of hypotheses regarding the processes operating within riverine ecosystems
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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