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1.
A new size-independent indicator of scientific journal prestige, the SJR2 indicator, is proposed. This indicator takes into account not only the prestige of the citing scientific journal but also its closeness to the cited journal using the cosine of the angle between the vectors of the two journals’ cocitation profiles. To eliminate the size effect, the accumulated prestige is divided by the fraction of the journal's citable documents, thus eliminating the decreasing tendency of this type of indicator and giving meaning to the scores. Its method of computation is described, and the results of its implementation on the Scopus 2008 dataset is compared with those of an ad hoc Journal Impact Factor, JIF(3y), and SNIP, the comparison being made both overall and within specific scientific areas. All three, the SJR2 indicator, the SNIP indicator and the JIF distributions, were found to fit well to a logarithmic law. Although the three metrics were strongly correlated, there were major changes in rank. In addition, the SJR2 was distributed more equalized than the JIF by Subject Area and almost as equalized as the SNIP, and better than both at the lower level of Specific Subject Areas. The incorporation of the cosine increased the values of the flows of prestige between thematically close journals. 相似文献
2.
《Journal of Informetrics》2014,8(1):181-196
The journal impact factor (JIF) reported in journal citation reports has been used to represent the influence and prestige of a journal. Whereas the consideration of the stochastic nature of a statistic is a prerequisite for statistical inference, the estimation of JIF uncertainty is necessary yet unavailable for comparing the impact among journals. Using journals in the Database of Research in Science Education (DoRISE), the current study proposes bootstrap methods to estimate the JIF variability. The paper also provides a comprehensive exposition of the sources of JIF variability. The collections of articles in the year of interest and in the preceding years both contribute to JIF variability. In addition, the variability estimate differs depending on the way a database selects its journals for inclusion. In the bootstrap process, the nested structure of articles in a journal was accounted for to ensure that each bootstrap replication reflects the actual citation characteristics of articles in the journal. In conclusion, the proposed point and interval estimates of the JIF statistic are obtained and more informative inferences on the impact of journals can be drawn. 相似文献
3.
《Journal of Informetrics》2022,16(3):101315
In 2021, Clarivate published a new version of the Journal Citation Reports (JCR) including a new indicator. The Journal Citation Indicator (JCI) is a new field-normalized metric at journal-level, which is calculated by averaging the Category Normalized Citation Impact (CNCI) of the journal's articles and reviews published in the preceding three-year period. Unlike the Journal Impact Factor (JIF), it is also calculated for the journals of the Arts & Humanities Citation Index (AHCI) and the Emerging Sources Citation Index (ESCI), which are now included in the JCR. To better understand this new indicator, this article analyses its main statistical characteristics in comparison with the other JCR indicators using all JCR journals and categories. The results highlight the similarities between the JCI and JIF, with a high Pearson correlation (0.853) and a similar distribution. This correlation is also high and homogeneous in the different categories, both for Science and Social Sciences. The JCI is therefore a perfect complement to the JIF, as well as representing an alternative to resolve the well-known problems of the JCR. 相似文献
4.
The journal impact factor (JIF) is the average of the number of citations of the papers published in a journal, calculated according to a specific formula; it is extensively used for the evaluation of research and researchers. The method assumes that all papers in a journal have the same scientific merit, which is measured by the JIF of the publishing journal. This implies that the number of citations measures scientific merits but the JIF does not evaluate each individual paper by its own number of citations. Therefore, in the comparative evaluation of two papers, the use of the JIF implies a risk of failure, which occurs when a paper in the journal with the lower JIF is compared to another with fewer citations in the journal with the higher JIF. To quantify this risk of failure, this study calculates the failure probabilities, taking advantage of the lognormal distribution of citations. In two journals whose JIFs are ten-fold different, the failure probability is low. However, in most cases when two papers are compared, the JIFs of the journals are not so different. Then, the failure probability can be close to 0.5, which is equivalent to evaluating by coin flipping. 相似文献
5.
期刊引用认同指标在期刊评价中的适用性分析 总被引：1，自引：1，他引：0
论文以CSSCI图书情报领域的18种期刊为例,以这些期刊在2009年全年登载论文的参考文献为研究对象,从CSSCI数据库中获取数据,统计分析各期刊的引用认同。结果显示:期刊引用认同指标(引文量、篇均引文量、英文引文比、期刊引用广度、自施引率、引用半衰期、期刊集中因子、认同期刊影响力等指标)与CSSCI来源期刊定量与定性评价指标并不明显相关,但这类指标可以反映期刊载文的内容特征与偏好、对国外科学文献和对其他学科文献的利用程度、期刊的办刊定位、学科的发展模式等等,在综合评价期刊方面具有一定意义。 相似文献
6.
The journal impact factor (JIF) has been questioned considerably during its development in the past half-century because of its inconsistency with scholarly reputation evaluations of scientific journals. This paper proposes a publication delay adjusted impact factor (PDAIF) which takes publication delay into consideration to reduce the negative effect on the quality of the impact factor determination. Based on citation data collected from Journal Citation Reports and publication delay data extracted from the journals’ official websites, the PDAIFs for journals from business-related disciplines are calculated. The results show that PDAIF values are, on average, more than 50% higher than JIF results. Furthermore, journal ranking based on PDAIF shows very high consistency with reputation-based journal rankings. Moreover, based on a case study of journals published by ELSEVIER and INFORMS, we find that PDAIF will bring a greater impact factor increase for journals with longer publication delay because of reducing that negative influence. Finally, insightful and practical suggestions to shorten the publication delay are provided. 相似文献
7.
The paper introduces a new journal impact measure called The Reference Return Ratio (3R). Unlike the traditional Journal Impact Factor (JIF), which is based on calculations of publications and citations, the new measure is based on calculations of bibliographic investments (references) and returns (citations). A comparative study of the two measures shows a strong relationship between the 3R and the JIF. Yet, the 3R appears to correct for citation habits, citation dynamics, and composition of document types – problems that typically are raised against the JIF. In addition, contrary to traditional impact measures, the 3R cannot be manipulated ad infinitum through journal self-citations. 相似文献
8.
Borja González-Pereira Vicente P. Guerrero-Bote Félix Moya-Anegón 《Journal of Informetrics》2010,4(3):379-391
A size-independent indicator of journals’ scientific prestige, the SCImago Journal Rank (SJR) indicator, is proposed that ranks scholarly journals based on citation weighting schemes and eigenvector centrality. It is designed for use with complex and heterogeneous citation networks such as Scopus. Its computation method is described, and the results of its implementation on the Scopus 2007 dataset is compared with those of an ad hoc Journal Impact Factor, JIF(3y), both generally and within specific scientific areas. Both the SJR indicator and the JIF distributions were found to fit well to a logarithmic law. While the two metrics were strongly correlated, there were also major changes in rank. In addition, two general characteristics were observed. On the one hand, journals’ scientific influence or prestige as computed by the SJR indicator tended to be concentrated in fewer journals than the quantity of citation measured by JIF(3y). And on the other, the distance between the top-ranked journals and the rest tended to be greater in the SJR ranking than in that of the JIF(3y), while the separation between the middle and lower ranked journals tended to be smaller. 相似文献
9.
《Journal of Informetrics》2020,14(1):101007
This study compares the two-year impact factor (JIF2), JIF2 without journal self-citation (JIF2_noJSC), five-year impact factor (JIF5), eigenfactor score and article influence score (AIS) and investigates their relative changes with time. JIF2 increased faster than JIF5 overall. The relative change between JIF2 and JIF_noJSC shows that the control of JCR over journal self-citation is effective to some extent. JIF5 is more discriminative than JIF2. The correlation between JIF5 and AIS is stronger than that between JIF5 and the eigenfactor score. The relative change in journal rank according to different indicators varies with the ratio of the indicators and can be up to 60 % of the number of journals in a subject category. There is subject category discrepancy in the average AIS and its change over time. Through the screening of journals according to variations in the ratio of JIF2 to JIF5 for journals in individual subject categories, we found that journals in the same subject categories can have considerably different citation patterns. To provide a fair comparison of journals in individual subject categories, we argue that it is better to replace JIF2 with the ready-made JIF5 when ranking journals. 相似文献
10.
《Journal of Informetrics》2022,16(3):101305
This study examined the development of English-language journals indexed by the database of Journal Citation Reports (JCR) and owned by six non-English-speaking countries (China, Japan, South Korea, Taiwan, Italy, and Spain) and four countries where English is an official national language (Australia, Canada, India, and Singapore) over a 21-year period. Four types of journals were identified based on changes in journal impact factor (JIF) and rank percentage per year. The results suggest that “growth” journals with trends of increasing JIF and rank percentage outnumbered other types of journals for each country and were not concentrated in particular subject categories. Over half of the growth journals in eight countries were positioned at Q3 and Q4 levels. No significant differences in the average age of growth journals were identified between countries. Although China possessed the highest percentage of growth journals, its journals with the highest growth were at the Q4 level. This study concluded that China and South Korea should monitor their development of JCR journals due to their faster improvement in the average annual rank percentage per growth journal. One limitation is that a considerable proportion of junior English journals were not analyzed in this study. 相似文献
11.
《Journal of Informetrics》2007,1(1):47-58
This paper investigates the mechanism of the Journal Impact Factor (JIF). Although created as a journal selection tool the indicator is probably the central quantitative indicator for measuring journal quality. The focus is journal self-citations as the treatment of these in analyses and evaluations is highly disputed. The role of self-citations (both self-citing rate and self-cited rate) is investigated on a larger scale in this analysis in order to achieve statistical reliable material that can further qualify that discussion. Some of the hypotheses concerning journal self-citations are supported by the results and some are not. 相似文献
12.
In a recent paper in the Journal of Informetrics, Habibzadeh and Yadollahie [Habibzadeh, F., & Yadollahie, M. (2008). Journal weighted impact factor: A proposal. Journal of Informetrics, 2(2), 164–172] propose a journal weighted impact factor (WIF). Unlike the ordinary impact factor, the WIF of a journal takes into account the prestige or the influence of citing journals. In this communication, we show that the way in which Habibzadeh and Yadollahie calculate the WIF of a journal has some serious problems. Due to these problems, a ranking of journals based on WIF can be misleading. We also indicate how the problems can be solved by changing the way in which the WIF of a journal is calculated. 相似文献
13.
《Journal of Informetrics》2014,8(1):241-251
This study established a technological impact factor (TIF) derived from journal impact factor (JIF), which is proposed to evaluate journals from the aspect of practical innovation. This impact factor mainly examines the influence of journal articles on patents by calculating the number of patents cited to a journal divided by the number of articles published in that particular journal. The values of TIF for five-year (TIF5) and ten-year (TIF10) periods at the journal level and aggregated TIF values (TIFAGG_5 and TIFAGG_10) at the category level were provided and compared to the JIF. The results reveal that journals with higher TIF values showed varied performances in the JCR, while the top ten journals on JIF5 showed consistent good performance in TIFs. Journals in three selected categories – Electrical & Electronic Engineering, Research & Experimental Medicine, and Organic Chemistry – showed that TIF5 and TIF10 values are not strongly correlated with JIF5. Thus, TIFs can provide a new indicator for evaluating journals from the aspect of practical innovation. 相似文献
14.
The level of consensus in science has traditionally been measured by a number of different methods. The variety is important as each method measures different aspects of science and consensus. Citation analytical studies have previously measured the level of consensus using the scientific journal as their unit of analysis. To produce a more fine grained citation analysis one needs to study consensus formation on an even more detailed level – i.e. the scientific document or article. To do so, we have developed a new technique that measures consensus by aggregated bibliographic couplings (ABC) between documents. The advantages of the ABC-technique are demonstrated in a study of two selected disciplines in which the levels of consensus are measured using the proposed technique. 相似文献
15.
[目的/意义]数字人文作为新兴的跨学科研究领域,受到许多学科的广泛关注。本文旨在探析数字人文在图情档学科中的知识扩散,供数字人文和图情档发展借鉴。[方法/过程]以Web of Science核心数据集为数据来源,通过对数字人文在图情档的目标文献以及目标文献的图情档施引文献两部分数据的期刊扩散性和主题扩散性两个维度进行分析。其中,期刊扩散性采用来自传播学的期刊双向传播理论以及改良的消除时间因素影响的期刊引证系数两个指标进行分析,主题扩散性采用基于关键词的词云图和基于关键词的聚类进行分析。[结果/结论]研究表明,期刊双向传播中扩散性大于1的期刊共有13个,JOURNAL OF INFORMETRICS为双向扩散性能最好的期刊;数字人文在图情档学科所属学科期刊引证系数排名靠前的期刊有JOURNAL OF INFORMETRICS、SCIENTOMETRICS、JOURNAL OF THE ASSOCIATION FOR INFORMATION SCIENCE AND TECHNOLOGY等;期刊引证系数均呈现上下波动的现象,但是基本上top10的期刊在2006、2012、2016年出现了峰值,表明这些期刊在这些年份的影响力较大;数字人文研究现状、数字人文与图书馆融合、数字人文在教学中的应用、数字人文的激励措施在目标文献和施引文献的主题中均形成了规模,可以认为这四个方向的主题为数字人文在图情档的重点研究内容。 相似文献
16.
《Journal of Informetrics》2020,14(1):100989
The Journal Impact Factor (JIF) is linearly sensitive to self-citations because each self-citation adds to the numerator, whereas the denominator is not affected. Pinski and Narin (1976) Influence Weights (IW) are not or marginally sensitive to these outliers on the main diagonal of a citation matrix and thus provide an alternative to JIFs. Whereas the JIFs are based on raw citation counts normalized by the number of publications in the previous two years, IWs are based on the eigenvectors in the matrix of aggregated journal-journal citations without a reference to size: the cited and citing sides are normalized and combined by a matrix approach. Upon normalization, IWs emerge as a vector; after recursive multiplication of the normalized matrix, IWs can be considered a network measure of prestige among the journals in the (sub)graph under study. As a consequence, the self-citations are integrated at the field level and no longer disturb the analysis as outliers. In our opinion, this independence of the diagonal values is a very desirable property of a measure of quality or impact. As an example, we elaborate Price’s (1981b) matrix of aggregated citation among eight biochemistry journals in 1977. Routines for the computation of IWs are made available at http://www.leydesdorff.net/iw. 相似文献
17.
科学引文索引在生物医学领域的文献、作者、期刊评价中发挥着重要作用。F1000医学版的推出为医学文献、期刊的评价提供了新的途径。本研究的目的是通过对F1000医学版收录文献的分析并与SCI进行对比,研究SCI和F1000医学版对评价医学期刊的差异,为有效提高医教研水平提供帮助。方法：获取F1000医学版从推出到2011年11月收录的被推荐文献,按照所属期刊、年度进行统计分析。通过检索medline获得各种期刊、各年度的发表文献总量,获得各种期刊、各年度的推荐比并排序,并与SCI相对比。结果：F1000医学版与SCI共同收录的医学期刊共1620种。在这1620种期刊中,按推荐此、推荐文献量和IF值分别进行排序,相互之间排序结果相差较大。结论：F1000医学版对评价医学期刊的权威性的评价与SCI存在较大差异。F1000医学版的评价在对医学期刊的评价中发挥着与SCI同等重要的作用。 相似文献
18.
期刊评价指标SJR、JIF和H指数的关系研究 总被引：4，自引：1，他引：3
19.