Some comments on the journal weighted impact factor proposed by Habibzadeh and Yadollahie

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.     

Mathematical derivation of the impact factor distribution

Experimental data [Mansilla, R., Köppen, E., Cocho, G., & Miramontes, P. (2007). On the behavior of journal impact factor rank-order distribution. Journal of Informetrics, 1(2), 155–160] reveal that, if one ranks a set of journals (e.g. in a field) in decreasing order of their impact factors, the rank distribution of the logarithm of these impact factors has a typical S-shape: first a convex decrease, followed by a concave decrease. In this paper we give a mathematical formula for this distribution and explain the S-shape. Also the experimentally found smaller convex part and larger concave part is explained. If one studies the rank distribution of the impact factors themselves, we now prove that we have the same S-shape but with inflection point in μ, the average of the impact factors. These distributions are valid for any type of impact factor (any publication period and any citation period). They are even valid for any sample average rank distribution.     

Some comments on Egghe's derivation of the impact factor distribution

In a recent paper, Egghe [Egghe, L. (in press). Mathematical derivation of the impact factor distribution. Journal of Informetrics] presents a mathematical analysis of the rank-order distribution of journal impact factors. The analysis is based on the central limit theorem. We criticize the empirical relevance of Egghe's analysis. More specifically, we argue that Egghe's analysis relies on an unrealistic assumption and we show that the analysis is not in agreement with empirical data.     

Empirical modeling of the impact factor distribution

The distribution of impact factors has been modeled in the recent informetric literature using two-exponent law proposed by Mansilla, Köppen, Cocho, and Miramontes (2007). This paper shows that two distributions widely-used in economics, namely the Dagum and Singh-Maddala models, possess several advantages over the two-exponent model. Compared to the latter, the former models give as good as or slightly better fit to data on impact factors in eight important scientific fields. In contrast to the two-exponent model, both proposed distributions have closed-from probability density functions and cumulative distribution functions, which facilitates fitting these distributions to data and deriving their statistical properties.     

高校学报影响因子与其所属高校综合实力的相关性

根据武书连"2012中国大学综合实力排行榜"和2012年版《中国科技期刊引证报告》的数据,对综合实力排名前10位的高校(排名)和其学报影响因子按学科分别进行了统计学相关性分析,同时对全国自然科学、人文社科类高校学报影响因子与其所属高校的排名进行了统计学相关性分析。结果表明,在一定条件下高校学报的影响因子与其高校排名存在一定相关性,但总体而言,相关性不强。     

Impact maturity times and citation time windows: The 2-year maximum journal impact factor

Journal metrics are employed for the assessment of scientific scholar journals from a general bibliometric perspective. In this context, the Thomson Reuters journal impact factors (JIFs) are the citation-based indicators most used. The 2-year journal impact factor (2-JIF) counts citations to one and two year old articles, while the 5-year journal impact factor (5-JIF) counts citations from one to five year old articles. Nevertheless, these indicators are not comparable among fields of science for two reasons: (i) each field has a different impact maturity time, and (ii) because of systematic differences in publication and citation behavior across disciplines. In fact, the 5-JIF firstly appeared in the Journal Citation Reports (JCR) in 2007 with the purpose of making more comparable impacts in fields in which impact matures slowly. However, there is not an optimal fixed impact maturity time valid for all the fields. In some of them two years provides a good performance whereas in others three or more years are necessary. Therefore, there is a problem when comparing a journal from a field in which impact matures slowly with a journal from a field in which impact matures rapidly. In this work, we propose the 2-year maximum journal impact factor (2M-JIF), a new impact indicator that considers the 2-year rolling citation time window of maximum impact instead of the previous 2-year time window. Finally, an empirical application comparing 2-JIF, 5-JIF, and 2M-JIF shows that the maximum rolling target window reduces the between-group variance with respect to the within-group variance in a random sample of about six hundred journals from eight different fields.     

Relationship between an editor in chief's commentary publications and the impact factor of cardiovascular medicine journals

Journal impact factor (IF) inflation is suggested as a problem resulting from commentaries published by the editors in chief (EiCs) of their respective journals. However, it is unclear whether this is a systemic problem across the top thirty cardiovascular medicine journals. Therefore, the purpose of this investigation was to examine the relationship between the number of commentaries written by an EiC and their journal''s IF and Eigenfactor (Ef). Utilizing Spearman rank partial correlations controlling for length of service as the EiC, significant moderate correlations were found between the number of commentaries and the number of first-author commentaries by the EiC and the IF of their journal (r=0.568, p=0.001 and r=0.504, p=0.005; respectively). A weak but still significant correlation was found between the number of commentaries by the EiC and the Ef of their journal (r=0.431, p=0.020). The reason for these correlations is unclear, and whether the methodology used to compute the IF and Ef should be modified needs further research.     

Technological impact factor: An indicator to measure the impact of academic publications on practical innovation

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 (TIF_{AGG_5} and TIF_{AGG_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.     

论用期刊影响因子评价论文作者的逻辑前提与局限性

目前,用期刊的影响因子取代论文的实际引用次数来评价作者或科研成果,是一个有争议的问题.从影响因子的概念、应用于评价的前提条件和其局限性等方面入手,分析采用期刊影响因子来评价论文作者可能存在的问题,为合理地将影响因子作为科研绩效评价工具提供参考.     

如何提高英文版科技期刊的被引频次和影响因子

从总被引频次和影响因子2方面分析我国英文版科技期刊的引用指标的现状和引用指标偏低的原因.提出了提高英文版科技期刊被引频次和影响因子的措施:1)注重期刊的国内外发行工作;2)通过建立英文网站及加入国内外知名数据库,提高文章的点击率及浏览量;3)请专家把语言关.     

消除唯SCI影响因子对我国科技期刊发展的危害刻不容缓

近年来我国英文科技期刊发展迅速,但在期刊出版、评价、管理等过程中,唯SCI影响因子的现象越发明显.由于影响因子本身的局限性,唯影响因子在期刊基础设施建设、论文选择与评审、期刊竞争力提升等方面带来严重的不利影响,消除唯SCI影响因子对我国科技期刊发展的危害刻不容缓.不局限于少数指标,让不同类型的期刊都能得到充分发展,这样才能壮大中国科技期刊的整体实力.     

中国、印度计算机科学领域论文影响力的比较研究

文章以1999-2008年Science Citation Index--Expanded为数据来源,从发文数量、被引频次、发文期刊的时间分布、期刊影响因子、被引频次等方面对中国和印度两国在计算机科学领域内论文的发文情况进行了比较研究。     

期刊影响力指数与影响因子评价国际期刊的比较研究

为了验证《中国学术期刊(光盘版)》电子杂志社提出的新型期刊评价指标——期刊影响力指数(Journal Clout Index,CI)的科学性,首先采用JCR数据分析影响因子(IF)与5年影响因子(IF5)、IF与即年指标(IM)、IF与总被引频次(TC)之间的相关性,得出结论:IF、IF5、IM是相关性显著的同类指标,IF与TC的相关性较弱;因而认为,TC和IF是可用来评价期刊影响力的主要指标,基于这2个指标的综合评价指标——期刊影响力指数(CI)具有合理性.进一步实证分析了CI这一综合指标对国际期刊的排序结果比采用单一指标——影响因子(IF)排序更符合实际经验认识.     

论用期刊影响因子评价论文作者的逻辑前提与局限性

目前,用期刊的影响因子取代论文的实际引用次数来评价作者或科研成果,是一个争议的问题.从影响因子的概念、应用于评价的前提条件和其局限性等方面入手,分析采用期刊影响因子来评价论文作者可能存在的问题,为合理地将影响因子作为科研绩效评价工具提供参考.     

A user-centric approach to identifying best deployment strategies for language tools: the impact of content and access language on Web user behaviour and attitudes

The number of Web users whose first language is not English continues to grow, as does the amount of content provided in languages other than English. This poses new challenges for actors on the Web, such as in which language(s) content should be offered, how search tools should deal with mono- and multilingual content, and how users can make the best use of navigation and search options, suited to their individual linguistic skills. How should these challenges be dealt with? Technological approaches to non-English (or in general, cross-language) Web search have made large progress; however, translation remains a hard problem. This precludes a low-cost but high-quality blanket all-language coverage of the whole Web. In this paper, we propose a user-centric approach to answering questions of where to best concentrate efforts and investments. Drawing on linguistic research, we describe data on the availability of content and access to it in first and second languages across the Web. We then present three studies that investigated the impact of the availability (or not) of first-language content and access forms on user behaviour and attitudes. The results indicate that non-English languages are under-represented on the Web and that this is partly due to content-creation, link-setting and link-following behaviour. They also show that user satisfaction is influenced both by the cognitive effort of searching and the availability of alternative information in that language. These findings suggest that more cross-language tools are desirable. However, they also indicate that context (such as user groups’ domain expertise or site type) should be considered when tradeoffs between information quality and multilinguality need to be taken into account.     

On the relation between the degree of internationalization of cited and citing publications: A field level analysis,including and excluding self-citations

The growing complexity of scientific challenges demands increasingly intense research collaboration, both domestic and international. The resulting trend affects not only the modes of producing new knowledge, but also the way it is disseminated within scientific communities. This paper analyses the relationship between the “degree of internationalization” of a country’s scientific production and that of the relevant citing publications. The empirical analysis is based on 2010-2012 Italian publications. Findings show: i) the probability of being cited increases with the degree of internationalization of the research team; ii) totally domestic research teams tend to cite to a greater extent totally domestic publications; iii) vice versa, publications resulting from international collaborations tend to be more cited by totally foreign publications rather than by publications including domestic authors. These results emerge both at overall and at discipline level. Findings might inform research policies geared towards internationalization.     

Unraveling the relationships between smartphone use,exposure to heterogeneity,political efficacy,and political participation: a mediation model approach

This paper assesses how use of smartphones relates to exposure to heterogeneity, political efficacy, and political engagement and suggests a new mediation model that can be applied to mobile communication. Drawing on online survey data collected during the 2012 presidential election in South Korea, this study finds that exposure to heterogeneity and political efficacy jointly mediate the impact of informational uses of smartphones on political participation. The current study also shows that informational uses of smartphones are significantly related to encounters with heterogeneity, political efficacy, and participatory behaviors. Additionally, recreational uses of smartphones were found to have a positive association with exposure to heterogeneity. However, relational uses of smartphones were not associated with democratic outcomes. The findings suggest that smartphones, by increasing the possibility of encountering diversity and subsequently enhancing political efficacy, create an additional pathway to citizen engagement in democratic processes.