1,720,992 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
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
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
Nature Index. General framework, statistical method and data collection for Norway
Full text linkCertain, G. and Skarpaas, O. 2010. Nature Index: General framework, statistical method and data collection for Norway – NINA Report 542. 47 pp.
The Nature Index for Norway has been developed to be an aggregated measure of biodiversity in Norway, reflecting the state of terrestrial and marine ecosystems and providing comprehensive information to environmental managers and to the public in a simplified and understandable way. It consists of a set of 310 biodiversity indicators that encompass important aspects of natural biodiversity. The present report is a general description of the Nature Index framework. It summarises the basic concepts and definitions used, and displays the associated mathematical developments. The report builds on and extends previous pilot studies on concepts and practical implementation (NINA Reports 347, 425 and 426). The final results of the Nature Index will be presented elsewhere (Nybø (ed.) 2010a,b); here we present the data collection process and an analysis of the indicator set collected so far in order to provide information on the ecological significance and on the inferences that can be expected. Data on indicators were collected from experts who provided estimates of the indicator values at several points in time using expert judgement, monitoring data or models. Experts also provided an estimate of uncertainty with each data point in the form of quartiles, and they were asked to indicate where insufficient information was available to provide an estimate of the indicator value. To combine the indicators to produce an index, the indicators are scaled by a reference value, i.e. their value in a reference state. This serves two purposes: First, the reference state, for each indicator, is supposed to reflect an ecologically sustainable state for the indicator, and the scaled value measures the departure from this state. Second, because the scaled values are all dimensionless numbers between 0 and 1, they can be averaged across, for instance, municipality, major habitat, or taxonomic group. Thus the use of a reference value facilitates a flexible combination of indicators expressed in different measurement units, such as abundance or species richness. Plain averaging of scaled indicators implies a “complete equivalence” assumption, i.e. that no municipality, no major habitat, and no indicator is more important than another. This assumption is not always true. Moreover, despite efforts to balance the indicator set, the indicators are not homogeneously distributed among taxonomic groups, pressures, major habitats etc. In the specific case of Norway, we decided, with the support of the Ecological Reference group for the Nature Index, to apply weighting mainly to deal with heterogeneities within the indicator set. Weights were applied across two axes of the Nature Index: across the spatial axis, so that the index remains area-representative, and across the indicator axis, to solve issues concerning the ecological significance of the index. Equivalence was maintained between major habitats because this ensures that the nature index will be maximised with beta (regional) diversity as well as alpha (local) diversity: complete loss of a major habitat implies a decrease in beta diversity, and this will always result in a decrease of the index under equivalence between major habitats. biodiversity, indicators, Norway, biologisk mangfold, indikatorer, NorgeCertain, G. and Skarpaas, O. 2010. Nature Index: General framework, statistical method and data collection for Norway – NINA Rapport 542. 47 s.
Naturindeksen er et sammensatt mål for biologisk mangfold i Norge som gjenspeiler tilstanden i terrestre og marine natursystemer og formidler denne omfattende informasjonen til miljøforvaltningen og allmenheten på en forenklet og forståelig måte. Den består av 310 indikatorer som dekker viktige aspekter ved biologisk mangfold.
Denne rapporten gir en generell beskrivelse av rammeverket for Naturindeksen. Den gjennomgår grunnleggende begreper og definisjoner, og tilhørende matematiske formuleringer. Rapporten bygger videre på tidligere forslag til rammeverk og pilotstudier (NINA Rapport 347, 425 og 426). Hovedresultatene for naturindeksen presenteres i to kommende DN-utredninger (Nybø (ed.) 2010a,b); her presenterer vi metoder for datainnsamling og en analyse av indikatorsettet for å informere om den økologiske betydningen av naturindeksen og slutningene man kan forvente å gjøre på grunnlag av denne.
Data om indikatorene ble samlet inn fra eksperter som ga estimater av indikatorverdier på flere tidspunkter på grunnlag av ekspertvurderinger, overvåkingsdata eller modeller. Ekspertene ga
også et estimat av usikkerheten til hver verdi i form av kvartiler, og de ble bedt om å angi i hvilke tilfeller grunnlaget var for svakt til å gi estimater.
For å kunne kombinere indikatorene til en indeks, ble hver enkelt indikator skalert med en referanseverdi, dvs. verdien av indikatoren i en referansetilstand. Dette tjener to formål: For det første reflekterer referansetilstanden en økologisk bærekraftig tilstand for indikatoren, og den skalerte verdien måler avvik fra denne tilstanden. For det andre kan de skalerte verdiene, som alle er enhetsløse verdier mellom null og en, benyttes til å beregne gjennomsnitt på tvers av for eksempel kommuner, hovedgrupper av natursystemer og taksonomiske grupper. Bruken av en referanse muliggjør dermed fleksible kombinasjoner av indikatorer med ulike måleenheter som bestandsstørrelse eller artsrikdom.
Rene gjennomsnitt av skalerte indikatorverdier kan beregnes under en antagelse om ”fullstendig ekvivalens”, dvs. at ingen kommune, ingen natursystemer og ingen indikatorer er viktigere enn andre. Dette vil ikke alltid være tilfelle. Indikatorene er heller ikke jevnt fordelt mellom taksonomiske grupper, påvirkninger, etc., på tross av forsøk på å balansere indikatorsettet. I implementeringen for Norge har vi derfor valgt, med støtte fra Faggruppen for Naturindeksen, å tilordne vekter langs to akser: den geografiske aksen, slik at indeksen blir arealrepresentativ, og indikatoraksen, for å løse problemer med økologisk representativitet. Mellom hovedgrupper av natursystemer antar vi fullstendig ekvivalens, fordi dette sikrer at Naturindeksen maksimeres med betadiversitet (regional diversitet), i tillegg til alfadiversitet
(lokal diversitet): tap av et natursystem medfører reduksjon i betadiversitet, og dette medfører alltid en reduksjon i indeksen under antagelsen om fullstendig ekvivalens.
I Naturindeksen brukes datausikkerhet og manglende data aktivt på flere måter: Informasjon om kilder til indikatorestimater (ekspertvurdering, data, modeller), usikkerheten i estimatene og tilfeller med fullstendig mangel på kunnskap, kan brukes til å målrette framtidig forskning og utredning. Usikkerhet i indikatorestimater aggregeres til indeksnivå ved hjelp av Monte Carlometoder: simulering av fordelingene tilpasset gjennomsnitt og kvartiler til hver enkelt indikator.
Naturindeksen kan fange opp og sammenstille informasjon fra ulike økologiske fagfelt, både terrestre og marine, og avlevere to hovedtyper av informasjon: tilstanden til natursystemer, gitt dagens kunnskap, og områder med manglende kunnskap kan begge tydeliggjøres og gi innspill til forvaltning og forskning. Informasjonen i naturindeksen kan aggregeres eller splittes opp langs flere akser, slik som geografiske enheter, økologiske enheter eller forvaltningstema.
Dette gir Naturindeksen et stort potensial som forvaltningsverktøy og katalysator for økologisk forskning og utredning i Norge, og for internasjonal anvendelse
Biodiversity baseline for large marine ecosystems: an example from the Barents Sea
No full textBiodiversity is an increasingly important issue for the management of marine ecosystems. However, the proliferation of biodiversity indices and difficulties associated with their interpretation have resulted in a lack of clearly defined framework for quantifying biodiversity and biodiversity changes in marine ecosystems for assessment purpose. Recent theoretical and numerical developments in biodiversity statistics have established clear algebraic relationships between most of the diversity measures commonly used, and have highlighted those that most directly relates to the concept of biological diversity, terming them "true" diversity measures. In this study, we implement the calculation of these "true" diversity measures at the scale of a large-marine ecosystem, the Barents Sea. We applied hierarchical partitioning of biodiversity to an extensive dataset encompassing 10 years of trawl-surveys for both pelagic and demersal fish community. We quantify biodiversity and biodiversity changes for these two communities across the whole continental shelf of the Barents Sea at various spatial and temporal scales, explicitly identifying areas where fish communities are stable and variable. The method is used to disentangle areas where community composition is subject to random fluctuations from areas where the fish community is drifting over time. We discuss how our results can serve as a spatio-temporal biodiversity baseline against which new biodiversity estimates, derived from sea surveys, can be evaluated
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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