共查询到20条相似文献，搜索用时 46 毫秒
1.
In the double rank analysis of research publications, the local rank position of a country or institution publication is expressed as a function of the world rank position. Excluding some highly or lowly cited publications, the double rank plot fits well with a power law, which can be explained because citations for local and world publications follow lognormal distributions. We report here that the distribution of the number of country or institution publications in world percentiles is a double rank distribution that can be fitted to a power law. Only the data points in high percentiles deviate from it when the local and world μ parameters of the lognormal distributions are very different. The likelihood of publishing very highly cited papers can be calculated from the power law that can be fitted either to the upper tail of the citation distribution or to the percentile-based double rank distribution. The great advantage of the latter method is that it has universal application, because it is based on all publications and not just on highly cited publications. Furthermore, this method extends the application of the well-established percentile approach to very low percentiles where breakthroughs are reported but paper counts cannot be performed. 相似文献
2.
Reliable methods for the assessment of research success are still in discussion. One method, which uses the likelihood of publishing very highly cited papers, has been validated in terms of Nobel prizes garnered. However, this method cannot be applied widely because it uses the fraction of publications in the upper tail of citation distribution that follows a power law, which includes a low number of publications in most countries and institutions. To achieve the same purpose without restrictions, we have developed the double rank analysis, in which publications that have a low number of citations are also included. By ranking publications by their number of citations from highest to lowest, publications from institutions or countries have two ranking numbers: one for their internal and another one for world positions; the internal ranking number can be expressed as a function of the world ranking number. In log–log double rank plots, a large number of publications fit a straight line; extrapolation allows estimating the likelihood of publishing the highest cited publication. The straight line derives from a power law behavior of the double rank that occurs because citations follow lognormal distributions with values of μ and σ that vary within narrow limits. 相似文献
3.
《Journal of Informetrics》2014,8(4):963-971
Citations are increasingly used for research evaluations. It is therefore important to identify factors affecting citation scores that are unrelated to scholarly quality or usefulness so that these can be taken into account. Regression is the most powerful statistical technique to identify these factors and hence it is important to identify the best regression strategy for citation data. Citation counts tend to follow a discrete lognormal distribution and, in the absence of alternatives, have been investigated with negative binomial regression. Using simulated discrete lognormal data (continuous lognormal data rounded to the nearest integer) this article shows that a better strategy is to add one to the citations, take their log and then use the general linear (ordinary least squares) model for regression (e.g., multiple linear regression, ANOVA), or to use the generalised linear model without the log. Reasonable results can also be obtained if all the zero citations are discarded, the log is taken of the remaining citation counts and then the general linear model is used, or if the generalised linear model is used with the continuous lognormal distribution. Similar approaches are recommended for altmetric data, if it proves to be lognormally distributed. 相似文献
4.
Gabriel-Alexandru Vîiu 《Journal of Informetrics》2018,12(2):401-415
Characteristic scores and scales (CSS) – a well-established scientometric tool for the study of citation counts – have been used to document a striking phenomenon that characterizes citation distributions at high levels of aggregation: irrespective of scientific field and citation window empirical studies find a persistent pattern whereby about 70% of scientific papers belong to the class of poorly cited papers, about 21% belong to the class of fairly cited papers, 6% to that of remarkably cited papers and 3% to the class of outstandingly cited papers. This article aims to advance the understanding of this remarkable result by examining it in the context of the lognormal distribution, a popular model used to describe citation counts across scientific fields. The article shows that the application of the CSS method to lognormal distributions provides a very good fit to the 70–21–6–3% empirical pattern provided these distributions are characterized by a standard deviation parameter in the range of about 0.8–1.3. The CSS pattern is essentially explainable as an epiphenomenon of the lognormal functional form and, more generally, as a consequence of the skewness of science which is manifest in heavy-tailed citation distributions. 相似文献
5.
We address issues concerning what one may learn from how citation instances are distributed in scientific articles. We visualize and analyze patterns of citation distributions in the full text of 350 articles published in the Journal of Informetrics. In particular, we visualize and analyze the distributions of citations in articles that are organized in a commonly seen four-section structure, namely, introduction, method, results, and conclusions (IMRC). We examine the locations of citations to the groundbreaking h-index paper by Hirsch in 2005 and how patterns associated with citation locations evolve over time. The results show that citations are highly concentrated in the first section of an article. The density of citations in the first section is about three times higher than that in subsequent sections. The distributions of citations to highly cited papers are even more uneven. 相似文献
6.
Mike Thelwall 《Journal of Informetrics》2019,13(2):658-678
Articles are cited for different purposes and differentiating between reasons when counting citations may therefore give finer-grained citation count information. Although identifying and aggregating the individual reasons for each citation may be impractical, recording the number of citations that originate from different article sections might illuminate the general reasons behind a citation count (e.g., 110 citations = 10 Introduction citations + 100 Methods citations). To help investigate whether this could be a practical and universal solution, this article compares 19 million citations with DOIs from six different standard sections in 799,055 PubMed Central open access articles across 21 out of 22 fields. There are apparently non-systematic differences between fields in the most citing sections and the extent to which citations from one section overlap with citations from another, with some degree of overlap in most cases. Thus, at a science-wide level, section headings are partly unreliable indicators of citation context, even if they are more standard within individual fields. They may still be used within fields to help identify individual highly cited articles that have had one type of impact, especially methodological (Methods) or context setting (Introduction), but expert judgement is needed to validate the results. 相似文献
7.
《Legal Reference Services Quarterly》2013,32(2-3):99-112
Abstract Several studies have compared the frequency of citation to law reviews, comparing citation rates for all or most law reviews being published at the time of the study. This article compares the citation rates of general law reviews published by seven public law schools in close geographic proximity. The results show that citation rates are influenced by several factors, including whether articles published by the journals have a state or national focus, the subject matter of the articles, and whether articles are published as part of symposia. 相似文献
8.
《Journal of Informetrics》2014,8(4):863-872
Delayed recognition is a concept applied to articles that receive very few to no citations for a certain period of time following publication, before becoming actively cited. To determine whether such a time spent in relative obscurity had an effect on subsequent citation patterns, we selected articles that received no citations before the passage of ten full years since publication, investigated the subsequent yearly citations received over a period of 37 years and compared them with the citations received by a group of papers without such a latency period. Our study finds that papers with delayed recognition do not exhibit the typical early peak, then slow decline in citations, but that the vast majority enter decline immediately after their first – and often only – citation. Middling papers’ citations remain stable over their lifetime, whereas the more highly cited papers, some of which fall into the “sleeping beauty” subtype, show non-stop growth in citations received. Finally, papers published in different disciplines exhibit similar behavior and did not differ significantly. 相似文献
9.
Kevin W. Boyack Nees Jan van Eck Giovanni Colavizza Ludo Waltman 《Journal of Informetrics》2018,12(1):59-73
We report characteristics of in-text citations in over five million full text articles from two large databases – the PubMed Central Open Access subset and Elsevier journals – as functions of time, textual progression, and scientific field. The purpose of this study is to understand the characteristics of in-text citations in a detailed way prior to pursuing other studies focused on answering more substantive research questions. As such, we have analyzed in-text citations in several ways and report many findings here. Perhaps most significantly, we find that there are large field-level differences that are reflected in position within the text, citation interval (or reference age), and citation counts of references. In general, the fields of Biomedical and Health Sciences, Life and Earth Sciences, and Physical Sciences and Engineering have similar reference distributions, although they vary in their specifics. The two remaining fields, Mathematics and Computer Science and Social Science and Humanities, have different reference distributions from the other three fields and between themselves. We also show that in all fields the numbers of sentences, references, and in-text mentions per article have increased over time, and that there are field-level and temporal differences in the numbers of in-text mentions per reference. A final finding is that references mentioned only once tend to be much more highly cited than those mentioned multiple times. 相似文献
10.
Multidisciplinary cooperation is now common in research since social issues inevitably involve multiple disciplines. In research articles, reference information, especially citation content, is an important representation of communication among different disciplines. Analyzing the distribution characteristics of references from different disciplines in research articles is basic to detecting the sources of referred information and identifying contributions of different disciplines. This work takes articles in PLoS as the data and characterizes the references from different disciplines based on Citation Content Analysis (CCA). First, we download 210,334 full-text articles from PLoS and collect the information of the in-text citations. Then, we identify the discipline of each reference in these academic articles. To characterize the distribution of these references, we analyze three characteristics, namely, the number of citations, the average cited intensity and the average citation length. Finally, we conclude that the distributions of references from different disciplines are significantly different. Although most references come from Natural Science, Humanities and Social Sciences play important roles in the Introduction and Background sections of the articles. Basic disciplines, such as Mathematics, mainly provide research methods in the articles in PLoS. Citations mentioned in the Results and Discussion sections of articles are mainly in-discipline citations, such as citations from Nursing and Medicine in PLoS. 相似文献
11.
哪些因素会影响学术论文的被引次数是文献计量学领域的一个经典研究议题。目前的研究主要关注论文的内容特征和形式特征与被引次数之间的关系,鲜有研究从文本可读性视角切入这一议题。文本可读性影响读者对文本内容的理解和知识吸收,是一个关乎知识传播效率和研究成果认可度的重要因素。本研究在控制论文知识品质和权威性的基础上,使用文本可读性R值等五个变量研究论文的文本可读性对被引次数的影响。以中文图书情报学知名期刊发表于2016—2020年的论文为研究样本,研究发现论文的文本可读性R值、是否采用复合式标题、是否使用公式和表格对被引次数有显著影响,而是否使用图对被引次数没有显著影响。研究验证了中文情境下文本可读性对论文影响力的实质性作用,研究结果对科研人员改善自身的中文学术写作以及提高研究成果影响力具有重要参考价值。 相似文献
12.
社会科学引文的离散性研究——基于JCR社科版指标分析 总被引：1，自引：0，他引：1
《期刊引证报告》(JCR)是美国科技信息研究所于1975年出版的一种独特的多学科期刊分析评价工具。通过对2005年的JCR社会科学版数据的统计分析可知,社会科学引文在基本符合布拉德福定律的情况下离散程度有所缩小,在社会科学领域较多的期刊承担着学术交流任务,因此不能笼统地说社会科学引文在期刊中的分布符合布拉德福定律,而应该注意到它的集中分散有一定的特殊性。 相似文献
13.
自存档文章引用优势案例分析研究 总被引：2，自引：1，他引：1
通过对自存档文章典型案例的引用情况进行分析研究,得出自存档文章存在引用优势的结论,并进一步对自存档文章引用优势的成因进行了分析,发现除了开放获取模式之外,先见优势、质量歧视、质量优势等因素都对自存档文章的引用优势做出了贡献。为了扩大研究影响和提高被引率,建议科学家应该积极将文章自存档。 相似文献
14.
《Journal of Informetrics》2019,13(2):738-750
An aspect of citation behavior, which has received longstanding attention in research, is how articles’ received citations evolve as time passes since their publication (i.e., citation ageing). Citation ageing has been studied mainly by the formulation and fit of mathematical models of diverse complexity. Commonly, these models restrict the shape of citation ageing functions and explicitly take into account factors known to influence citation ageing. An alternative—and less studied—approach is to estimate citation ageing functions using data-driven strategies. However, research following the latter approach has not been consistent in taking into account those factors known to influence citation ageing. In this article, we propose a model-free approach for estimating citation ageing functions which combines quantile regression with a non-parametric specification able to capture citation inflation. The proposed strategy allows taking into account field of research effects, impact level effects, citation inflation effects and skewness in the distribution of cites effects. To test our methodology, we collected a large dataset consisting of more than five million citations to 59,707 research articles spanning 12 dissimilar fields of research and, with this data in hand, tested the proposed strategy. 相似文献
15.
《Journal of Informetrics》2014,8(1):276-283
It is widely believed that collaboration is advantageous in science, for example, with collaboratively written articles tending to attract more citations than solo articles and strong arguments for the value of interdisciplinary collaboration. Nevertheless, it is not known whether the same is true for research that produces books. This article tests whether co-authored scholarly monographs attract more citations than solo monographs using books published before 2011 from 30 categories in the Web of Science. The results show that solo monographs numerically dominate collaborative monographs, but give no evidence of a citation advantage for collaboration on monographs. In contrast, for nearly all these subjects (28 out of 30) there was a citation advantage for collaboratively produced journal articles. As a result, research managers and funders should not incentivise collaborative research in book-based subjects or in research that aims to produce monographs, but should allow the researchers themselves to freely decide whether to collaborate or not. 相似文献
16.
In citation network analysis, complex behavior is reduced to a simple edge, namely, node A cites node B. The implicit assumption is that A is giving credit to, or acknowledging, B. It is also the case that the contributions of all citations are treated equally, even though some citations appear multiply in a text and others appear only once. In this study, we apply text-mining algorithms to a relatively large dataset (866 information science articles containing 32,496 bibliographic references) to demonstrate the differential contributions made by references. We (1) look at the placement of citations across the different sections of a journal article, and (2) identify highly cited works using two different counting methods (CountOne and CountX). We find that (1) the most highly cited works appear in the Introduction and Literature Review sections of citing papers, and (2) the citation rankings produced by CountOne and CountX differ. That is to say, counting the number of times a bibliographic reference is cited in a paper rather than treating all references the same no matter how many times they are invoked in the citing article reveals the differential contributions made by the cited works to the citing paper. 相似文献
17.
引文分析是指采用各种数理统计和逻辑方法对文献的引用频率、模式和图像进行计量研究。该文综述2009年以来国外在引文分析的基础理论、研究方法、研究前沿探测应用、引文指标四个方面的研究进展。 相似文献
18.
学术图书是学者研究成果的集中体现。作者在写作过程中,参考、引证了大量文献,将这些被引文献析出即形成索引。因此,将精选学术图书作为来源文献,创建图书引文数据库是现实可行的。基于这一设想,并付之于实践,即形成了《中文图书引文索引》(CBkCI)。该数据库以精选学术图书作为来源文献(统计源),统计、分析图书作者引用图书、期刊论文、报告等所有文献资料的情况。CBkCI示范数据库的研制成功,不仅填补了国内在图书引文领域的空白,促进学术图书出版质量的提升,而且有助于图书馆进行图书采访,精选馆藏,并为学术评价提供坚实的基础。 相似文献
19.
[目的/意义] 文章的被引频次一直是量化评价一篇论文学术影响力的重要指标。但在不同学科不同年份发表的论文会因该领域研究论文数、引用滞后等因素呈现较大的差异。因此在对比两篇论文时，难以简单依据被引频次的绝对值来评判论文影响力大小。为此，本文设计了一个新的可计算数学模型，使得每篇论文可以有一个标准化的指标，以便对不同学科不同年份发表的论文的学术影响力进行直接比较。[方法/过程] 通过分析2006、2017两年中国科技类学术期刊各学科论文的被引频次分布规律，采用同学科论文被引频次的分布形态最接近对数正态分布的先设条件，提出一种被引频次标准化指数——Paper Citation Standardized Index （简称PCSI，中文"论文引证标准化指数"）。最后以中国科协优秀科技期刊论文评选结果为例，将它们与论文所属学科全部论文进行实证对比研究。[结果/结论] 结果证明，PCSI对不同年份、不同学科论文的被引频次进行了标准化，反映了被引频次的线性差距，是一种较为理想的单篇论文学术影响力比较评价工具。 相似文献
20.
[目的/意义] 文章的被引频次一直是量化评价一篇论文学术影响力的重要指标。但在不同学科不同年份发表的论文会因该领域研究论文数、引用滞后等因素呈现较大的差异。因此在对比两篇论文时，难以简单依据被引频次的绝对值来评判论文影响力大小。为此，本文设计了一个新的可计算数学模型，使得每篇论文可以有一个标准化的指标，以便对不同学科不同年份发表的论文的学术影响力进行直接比较。[方法/过程] 通过分析2006、2017两年中国科技类学术期刊各学科论文的被引频次分布规律，采用同学科论文被引频次的分布形态最接近对数正态分布的先设条件，提出一种被引频次标准化指数——Paper Citation Standardized Index （简称PCSI，中文"论文引证标准化指数"）。最后以中国科协优秀科技期刊论文评选结果为例，将它们与论文所属学科全部论文进行实证对比研究。[结果/结论] 结果证明，PCSI对不同年份、不同学科论文的被引频次进行了标准化，反映了被引频次的线性差距，是一种较为理想的单篇论文学术影响力比较评价工具。 相似文献