共查询到20条相似文献，搜索用时 46 毫秒
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Michael Schreiber 《Journal of Informetrics》2010,4(4):647-651
The Hirsch index h and the g index proposed by Egghe as well as the f index and the t index proposed by Tol are shown to be special cases of a family of Hirsch index variants, based on the generalized mean with exponent p. Inequalities between the different indices are derived from the generalized mean inequality. The graphical determination of the indices is shown for one example. 相似文献
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Quentin L. Burrell 《Journal of Informetrics》2013,7(3):676-682
Empirical analysis of the relationship between the impact factor – as measured by the average number of citations – and the proportion of uncited material in a collection dates back at least to van Leeuwen and Moed (2005) where graphical presentations revealed striking patterns. Recently Hsu and Huang (2012) have proposed a simple functional relationship. Here it is shown that the general features of these observed regularities are predicted by a well-established informetric model which enables us to derive a theoretical van Leeuwen–Moed lower bound. We also question some of the arguments of Hsu and Huang (2012) and Egghe (2013) while various issues raised by Egghe, 2008, Egghe, 2013 are also addressed. 相似文献
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Suzan Verberne Maya Sappelli Djoerd Hiemstra Wessel Kraaij 《Information Retrieval》2016,19(5):510-545
We evaluate five term scoring methods for automatic term extraction on four different types of text collections: personal document collections, news articles, scientific articles and medical discharge summaries. Each collection has its own use case: author profiling, boolean query term suggestion, personalized query suggestion and patient query expansion. The methods for term scoring that have been proposed in the literature were designed with a specific goal in mind. However, it is as yet unclear how these methods perform on collections with characteristics different than what they were designed for, and which method is the most suitable for a given (new) collection. In a series of experiments, we evaluate, compare and analyse the output of six term scoring methods for the collections at hand. We found that the most important factors in the success of a term scoring method are the size of the collection and the importance of multi-word terms in the domain. Larger collections lead to better terms; all methods are hindered by small collection sizes (below 1000 words). The most flexible method for the extraction of single-word and multi-word terms is pointwise Kullback–Leibler divergence for informativeness and phraseness. Overall, we have shown that extracting relevant terms using unsupervised term scoring methods is possible in diverse use cases, and that the methods are applicable in more contexts than their original design purpose. 相似文献
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Ludo Waltman 《Journal of Informetrics》2012,6(4):700-711
There are different ways in which the authors of a scientific publication can determine the order in which their names are listed. Sometimes author names are simply listed alphabetically. In other cases, authorship order is determined based on the contribution authors have made to a publication. Contribution-based authorship can facilitate proper credit assignment, for instance by giving most credits to the first author. In the case of alphabetical authorship, nothing can be inferred about the relative contribution made by the different authors of a publication.In this paper, we present an empirical analysis of the use of alphabetical authorship in scientific publishing. Our analysis covers all fields of science. We find that the use of alphabetical authorship is declining over time. In 2011, the authors of less than 4% of all publications intentionally chose to list their names alphabetically. The use of alphabetical authorship is most common in mathematics, economics (including finance), and high energy physics. Also, the use of alphabetical authorship is relatively more common in the case of publications with either a small or a large number of authors. 相似文献
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《Journal of Informetrics》2007,1(2):170-177
Hirsch's h-index seeks to give a single number that in some sense summarizes an author's research output and its impact. Essentially, the h-index seeks to identify the most productive core of an author's output in terms of most received citations. This most productive set we refer to as the Hirsch core, or h-core. Jin's A-index relates to the average impact, as measured by the average number of citations, of this “most productive” core. In this paper, we investigate both the total productivity of the Hirsch core – what we term the size of the h-core – and the A-index using a previously proposed stochastic model for the publication/citation process, emphasising the importance of the dynamic, or time-dependent, nature of these measures. We also look at the inter-relationships between these measures. Numerical investigations suggest that the A-index is a linear function of time and of the h-index, while the size of the Hirsch core has an approximate square-law relationship with time, and hence also with the A-index and the h-index. 相似文献
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Jaime A. Teixeira da Silva 《Publishing Research Quarterly》2014,30(1):166-178
Snub publishing is a new term that was coined in 2013 to describe a range of publishing cases in which the failure of quality control manifested itself through references in such a way that it would cause unintended damage to snubbed scientists whose names or identity were incorrectly represented in the literature. In this paper, real case studies are presented, mostly related to the author as a “victim” of incompetent editorial oversight, inexperienced or biased authors, or as a “victim” of direct professional conflicts of interest. In essence, this paper serves as a prototype showing in concrete terms how a scientist can or may be professionally snubbed (intentionally or unintentionally). Using the Anthurium literature, this paper aims to raise awareness about snub publishing and seeks to encourage other scientists to also quantify how they too may have been professionally snubbed in the literature. 相似文献
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《Journal of Informetrics》2007,1(3):185-192
In this paper, we propose two methods for scoring scientific output based on statistical quantile plotting. First, a rescaling of journal impact factors for scoring scientific output on a macro level is proposed. It is based on normal quantile plotting which allows to transform impact data over several subject categories to a standardized distribution. This can be used in comparing scientific output of larger entities such as departments working in quite different areas of research. Next, as an alternative to the Hirsch index [Hirsch, J.E. (2005). An index to quantify an individuals scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569–16572], the extreme value index is proposed as an indicator for assessment of the research performance of individual scientists. In case of Lotkaian–Zipf–Pareto behaviour of citation counts of an individual, the extreme value index can be interpreted as the slope in a Pareto–Zipf quantile plot. This index, in contrast to the Hirsch index, is not influenced by the number of publications but stresses the decay of the statistical tail of citation counts. It appears to be much less sensitive to the science field than the Hirsch index. 相似文献
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《中国图书馆分类法》(以下简称《中图法》)(第5版)文学大类中部分类目在《中图法》(第4版)的基础上做了增加类目、修改类名等一系列修订,以此来增强类目的容纳性。但《中图法》(第5版)文学大类中的某些类目仍存在着类名不规范及类目关系错乱的问题。针对上述问题,可采取修改类名并增加注释、理顺类目之间逻辑关系等办法解决。 相似文献
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Antonio Quesada 《Journal of Informetrics》2011,5(3):476-480
The Hirsch index and the Egghe index are both numbers that synthesize a researcher's output. The h-index associated with researcher r is the maximum number h such that r has h papers with at least h citations each. The g-index is the maximum number g of papers by r such that the average number of citations of the g papers is at least g. Both indices are characterized in terms of four axioms. One identifies outputs deserving index at most one. A second one establishes a strong monotonicity condition. A third one requires the index to satisfy a property of subadditivity. The last one consists of a monotonicity condition, for the h-index, and an aggregate monotonicity condition, for the g-index. 相似文献
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《Journal of Informetrics》2007,1(1):59-67
Statistical distributions in the production of information are most often studied in the framework of Lotkaian informetrics. In this paper, we recall some results of basic theory of Lotkaian informetrics, then we transpose methods (Theorem 1) applied to Lotkaian distributions by Leo Egghe (Theorem 2) to the exponential distributions (Theorem 3, Theorem 4). We give examples and compare the results (Theorem 5). Finally, we propose to widen the problem using the concept of exponential informetric process (Theorem 6). 相似文献
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《Journal of Informetrics》2008,2(1):101-105
Egghe and Proot [Egghe, L., & Proot, G. (2007). The estimation of the number of lost multi-copy documents: A new type of informetrics theory. Journal of Informetrics] introduce a simple probabilistic model to estimate the number of lost multi-copy documents based on the numbers of retrieved ones. We show that their model in practice can essentially be described by the well-known Poisson approximation to the binomial. This enables us to adopt a traditional maximum likelihood estimation (MLE) approach which allows the construction of (approximate) confidence intervals for the parameters of interest, thereby resolving an open problem left by the authors. We further show that the general estimation problem is a variant of a well-known unseen species problem. This work should be viewed as supplementing that of Egghe and Proot [Egghe, L., & Proot, G. (2007). The estimation of the number of lost multi-copy documents: A new type of informetrics theory. Journal of Informetrics]. It turns out that their results are broadly in line with those produced by this rather more robust statistical analysis. 相似文献
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Tony Stankus 《Behavioral & Social Sciences Librarian》2013,32(4):20-56
ABSTRACT Psychologists, social workers, and school counselors are increasingly adding neurofeedback (NFT), a controversial alternative or complementary therapy to their treatment plans for patients with Attention Deficit Hyperactivity Disorder. NFT involves training the patient in self-regulation of brain wave patterns, employing a standard diagnostic tool, the EEG, in an interactive operant conditioning mode not often used by neurologists or psychiatrists. Some NFT therapists claim in their books that they have sufficient expertise to advise parents against the use of Ritalin? and amphetamines, which are part of the conventional multimodal therapy strongly endorsed in a wide variety of clinical publications. In return, some of the leading conventional physicians and Ph.D. researchers in the field of ADHD have traditionally ignored or disparaged the literature of NFT as being insufficiently scientific and appearing largely in obscure journals or books published outside the mainstream medical presses. While most librarians are unlikely to have sufficient scientific or clinical credentials to pass judgment, one way or another, on NFT as a treatment for ADHD, an examination of the credentials of authors, their books, book reviews, journals, and the publishers in which opponents and proponents make their case is entirely within our purview, and such an analysis is provided. 相似文献
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《The Reference Librarian》2013,54(49-50):95-104
Decades of research on the information-seeking behavior of scientists have shown heavy reliance on informal communication and personal collections. Entry into the literature is often gained through references in journal articles and other primary literature. This paper discusses these behaviors and some reasons for their use. Improvements in reference services to the scientific user community must be based on an understanding of scientific communication, information-seeking behavior, and the information needs of the user. Examples of user-oriented reference service are given. 相似文献
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Antonio Quesada 《Journal of Informetrics》2009,3(2):158-160
The Hirsch index is a number that synthesizes a researcher's output. It is the maximum number h such that the researcher has h papers with at least h citations each. Woeginger [Woeginger, G. J. (2008a). An axiomatic characterization of the Hirsch-index. Mathematical Social Sciences, 56(2), 224–232; Woeginger, G. J. (2008b). A symmetry axiom for scientific impact indices. Journal of Informetrics, 2(3), 298–303] characterizes the Hirsch index when indices are assumed to be integer-valued. In this note, the Hirsch index is characterized, when indices are allowed to be real-valued, by adding to Woeginger's monotonicity two axioms in a way related to the concept of monotonicity. 相似文献
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英文科技论文中常常出现一些包含前缀的人名.这些人名在名字写全和姓单独出现时,前缀首字母的大小写规则和前缀是否保留的原则视名字来源国家和传统习惯的不同而不同.本文详细梳理了不同国家人名中常见的前缀及其著录规则,并结合编辑工作实践中遇到的具体问题,分别对包含前缀人名出现在著者栏、正文和参考文献表中前缀的书写规则进行了辨析,以期能对编辑同人的工作提供帮助. 相似文献
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会议文献是重要的信息资源,但当前图书馆对其管理比较分散,资源建设缺乏系统性。对CPCI收录会议数据展开分析以了解其出版特点,结果发现：80％以上的会议文献在会议召开后两年内出版;会议文献在“工程技术”和“医药卫生”领域数量较多;连续性会议名称非常不规范等。在此基础上,对会议文献资源建设现状、难点进行了分析,并提出了有针对性的资源建设策略。 相似文献
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我国大陆港台医学期刊外文参考文献差错情况对照分析 总被引：2，自引：0，他引：2
分别从大陆、香港及台湾选取医学期刊,随机抽取2004年卷的80条文献,按照文献的6个项目进行核查.结果显示:存在差错的文献数量分别为大陆期刊48条(60.0%),台湾期刊40条(50.0%),香港期刊37条(46.3%);三者的差错率差异无统计学意义,同时3组统计文献差错类型的构成差别也没有统计学意义;差错情况中以作者姓名和题名最为突出.认为在知识信息时代,提高科技论文的文献著录质量和规范化水平,是作者、审稿人及期刊编辑均应重视的问题. 相似文献