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1.
学术论文是科研活动产出和知识信息交流的主要载体,而学术论文被引用则是学术成果获得认同的主要方式之一。研究高被引论文所引用论文的分布特征,对于了解高被引论文知识基础的构成具有重要意义。本文以ISI图书情报学（Information Science & Library Science）为例,以实证研究为基础,按比例采集图书情报学领域的高被引论文数据,查询这些高被引论文的参考文献的被引频次数据,以期得到高被引论文的引证特点。研究发现,图书情报学领域的高被引论文更多地引用了高被引参考文献;随着被引频次的降低,其引用的高被引论文所占的比例也在下降。  相似文献   

2.
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   

3.
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   

4.
[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   

5.
[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   

6.
Author keywords for scientific literature are terms selected and created by authors. Although most studies have focused on how to apply author keywords to represent their research interests, little is known about the process of how authors select keywords. To fill this research gap, this study presents a pilot study on author keyword selection behavior. Our empirical results show that the average percentages of author keywords appearing in titles, abstracts, and both titles and abstracts are 31%, 52.1%, and 56.7%, respectively. Meanwhile, we find that keywords also appear in references and high-frequency keywords. The proportions of author-selected keywords appearing in the references and high-frequency keywords are 41.6% and 56.1%, respectively. In addition, keywords of papers written by core authors (productive authors) are found to appear less frequently in titles and abstracts in their papers than that of others, and appear more frequently in references and high-frequency keywords. The percentages of keywords appearing in titles and abstracts in scientific papers are negatively correlated with citation counts of papers. In contrast, the percentages of author keywords appearing in high-frequency keywords are positively associated with citation counts of papers.  相似文献   

7.
[目的/意义]基于科学论文发表后的早期特征,准确预测论文未来的引文扩散演变模式,对科学产出评估、科学突破早期发现等都具有潜在的价值。[方法/过程]归纳总结9种不同的引文扩散演变模式,并基于论文自发表后的早期时序、结构和文献特征,建模预测未来一定引文窗口内的演变模式。选择美国物理学会的引文数据集进行实证研究,探究不同特征组合下引文扩散演变模式的预测效果。[结果/结论]结果显示,时序特征对预测模型的贡献程度最大,同时结构特征和文献特征也起到重要的作用,当融合3个特征时所有预测模型的准确率均超过了80%,证明了本文所选特征的有效性。  相似文献   

8.
Researchers have investigated factors thought to affect the total number of citations in various academic disciplines, and some general trends have emerged. However, there are still limited data for many fields, including aquatic sciences. Using papers published in 2003–2005 (n = 785), we investigated marine and freshwater biology articles to identify factors that may contribute to the probability of citation and for cumulative citation counts over 10 years. We found no relationships with probability of citation; however, we found evidence that for those that were cited at least once, cumulative citations were related to several factors. Articles cited by books received more citations than those never cited by books, which we hypothesized to be indicative of the impact an article may have in the field. We also found that articles first cited within 2 years of publication received more cumulative citations than those first cited after 2 years. We found no evidence that self‐citation (as the first citation) had a significant effect on total citations. Our findings were compared with previous studies in other disciplines, and it was found that aquatic science citation patterns are comparable to fields in science and technology but less so to humanities and social sciences.  相似文献   

9.
Citation behaviour is the source driver of scientific dynamics, and it is essential to understand its effect on knowledge diffusion and intellectual structure. This study explores the effect of citation behaviour on disciplinary knowledge diffusion and intellectual structure by comparing three types of citation behaviour trends, namely the high citation trend, medium citation trend, and low citation trend. The diffusion power, diffusion speed, and diffusion breadth were calculated to quantify knowledge diffusion. The properties of the global and local citation network structure were used to reflect the particular influences of citation behaviour on the scientific intellectual structure. The primary empirical results show that (a) the high citation behaviour trend could improve the knowledge diffusion speed for papers with a short citation history span. Additionally, the medium citation trend has the broadest diffusion breadth whereas the low citation behaviour trend might make the citation counts take off for papers with a long citation history span; (b) the high citation trend has a stronger influence and greater control over the intellectual structure, but this relationship is true only for papers with a short or normal citation history span. These findings could play important roles in scientific research evaluation and impact prediction.  相似文献   

10.
Despite citation counts from Google Scholar (GS), Web of Science (WoS), and Scopus being widely consulted by researchers and sometimes used in research evaluations, there is no recent or systematic evidence about the differences between them. In response, this paper investigates 2,448,055 citations to 2299 English-language highly-cited documents from 252 GS subject categories published in 2006, comparing GS, the WoS Core Collection, and Scopus. GS consistently found the largest percentage of citations across all areas (93%–96%), far ahead of Scopus (35%–77%) and WoS (27%–73%). GS found nearly all the WoS (95%) and Scopus (92%) citations. Most citations found only by GS were from non-journal sources (48%–65%), including theses, books, conference papers, and unpublished materials. Many were non-English (19%–38%), and they tended to be much less cited than citing sources that were also in Scopus or WoS. Despite the many unique GS citing sources, Spearman correlations between citation counts in GS and WoS or Scopus are high (0.78-0.99). They are lower in the Humanities, and lower between GS and WoS than between GS and Scopus. The results suggest that in all areas GS citation data is essentially a superset of WoS and Scopus, with substantial extra coverage.  相似文献   

11.
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   

12.
Various factors are believed to govern the selection of references in citation networks, but a precise, quantitative determination of their importance has remained elusive. In this paper, we show that three factors can account for the referencing pattern of citation networks for two topics, namely “graphenes” and “complex networks”, thus allowing one to reproduce the topological features of the networks built with papers being the nodes and the edges established by citations. The most relevant factor was content similarity, while the other two – in-degree (i.e. citation counts) and age of publication – had varying importance depending on the topic studied. This dependence indicates that additional factors could play a role. Indeed, by intuition one should expect the reputation (or visibility) of authors and/or institutions to affect the referencing pattern, and this is only indirectly considered via the in-degree that should correlate with such reputation. Because information on reputation is not readily available, we simulated its effect on artificial citation networks considering two communities with distinct fitness (visibility) parameters. One community was assumed to have twice the fitness value of the other, which amounts to a double probability for a paper being cited. While the h-index for authors in the community with larger fitness evolved with time with slightly higher values than for the control network (no fitness considered), a drastic effect was noted for the community with smaller fitness.  相似文献   

13.
本文创新性构建学术论文被引影响因素特征空间,以我校SCI&SSCI学术论文为例,验证机器学习模型在预测学术论文被引频次研究中的有效性和准确性,本文的分析结论可以为高校图书馆开展决策支持服务提供参考。本文梳理学术论文被引频次影响因素及预测方法的相关研究,结合传统文献计量和Altmetrics指标构建学术论文影响因素的特征空间,并通过实验比较线性回归、神经网络、支持向量机三种机器学习模型在预测学术论文被引频次研究中的有效性和准确性。本文的分析结论证明基于Altmetrics视角构建的特征空间的预测准确率大幅度提高,并且支持向量机模型在对学术论文影响力预测的实证研究中表现出优异的性能。  相似文献   

14.
Predicting the citation counts of academic papers is of considerable significance to scientific evaluation. This study used a four-layer Back Propagation (BP) neural network model to predict the five-year citations of 49,834 papers in the library, information and documentation field indexed by the CSSCI database and published from 2000 to 2013. We extracted six paper features, two journal features, nine author features, eight reference features, and five early citation features to make the prediction. The empirical experiments showed that the performance of the BP neural network is significantly better than those of the six baseline models. In terms of the prediction effect, the accuracy of the model at predicting infrequently cited papers was higher than that for frequently cited ones. We determined that five essential features have significant effects on the prediction performance of the model, i.e., ‘citations in the first two years’, ‘first-cited age’, ‘paper length’, ‘month of publication’, and ‘self-citations of journals’, and the other features contribute only slightly to the prediction.  相似文献   

15.
Modeling a century of citation distributions   总被引：1，自引：1，他引：0  
The prevalence of uncited papers or of highly cited papers, with respect to the bulk of publications, provides important clues as to the dynamics of scientific research. Using 25 million papers and 600 million references from the Web of Science over the 1900–2006 period, this paper proposes a simple model based on a random selection process to explain the “uncitedness” phenomenon and its decline over the years. We show that the proportion of cited papers is a function of (1) the number of articles available (the competing papers), (2) the number of citing papers and (3) the number of references they contain. Using uncitedness as a departure point, we demonstrate the utility of the stretched-exponential function and a form of the Tsallis q-exponential function to fit complete citation distributions over the 20th century. As opposed to simple power-law fits, for instance, both these approaches are shown to be empirically well-grounded and robust enough to better understand citation dynamics at the aggregate level. On the basis of these models, we provide quantitative evidence and provisional explanations for an important shift in citation practices around 1960. We also propose a revision of the “citation classic” category as a set of articles which is clearly distinguishable from the rest of the field.  相似文献   

16.
高Altmetrics指标科技论文学术影响力研究   总被引：9，自引：0，他引：9  
引入"公平性测试"方法以消除时间窗口对被引次数的影响。以高Altmetrics指标论文作为样本,选取与样本论文发表在同一期刊同一期上前后两篇论文作为参照。利用Altmetric.com、Web of Science分别获取273篇样本及参照论文的Altmetric分数、底层数据值和被引用次数。通过比较分析后发现:Altmetrics和引文数两种指标反映出读者对文献的不同关注方向,底层数据源中大众媒体对于Altmetric分数的影响最明显,高Altmetrics指标论文同时具有较高的学术影响力。作为一种早期指标,高Altmetrics指标在一定程度上能够被视作文章在未来获得高被引的风向标。  相似文献   

17.
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18.
Scientific production is steadily growing, exhibiting 4% annual growth in publications and 1.8% annual growth in the number of references per publication, together producing a 12-year doubling period in the total supply of references, i.e. links in the science citation network. This growth has far-reaching implications for how academic knowledge is connected, accessed and evaluated. Against this background, we analyzed a citation network comprised of 837 million references produced by 32.6 million publications over the period 1965–2012, allowing for a detailed analysis of the ‘attention economy’ in science. Our results show how growth relates to ‘citation inflation’, increased connectivity in the citation network resulting from decreased levels of uncitedness, and a narrowing range of attention – as both very classic and very recent literature are being cited increasingly less. The decreasing attention to recent literature published within the last 6 years suggests that science has become stifled by a publication deluge destabilizing the balance between production and consumption. To better understand these patterns together, we developed a generative model of the citation network, featuring exponential growth, the redirection of scientific attention via publications’ reference lists, and the crowding out of old literature by the new. We validate our model against several empirical benchmarks, and then use perturbation analysis to measure the impact of shifts in citing behavior on the synthetic system's properties, thereby providing insights into the functionality of the science citation network as an infrastructure supporting the memory of science.  相似文献   

19.
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   

20.
基于341位诺贝尔物理学、化学、生理学或医学、经济学奖获得者的引文曲线,借助曲线拟合方法构建引文曲线的分析框架,包括两种规则引文曲线——经典引文曲线、指数增长引文曲线,和三种不规则引文曲线——睡美人引文曲线、双峰引文曲线、波型引文曲线。以诺贝尔奖得主为例的实证分析表明:①引文曲线的分析框架是一种新的引文分析视角;②引文曲线的分析框架可用于将一组(有一定影响力的)论文或作者划分层次,也可用于分析不同学科论文或作者的引用差异。文章最后分析了该框架的适用性。图4。表1。参考文献32。  相似文献   

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