The effect of additional citations in the stability of Journal Citation Report categories

We use a new approach to study the ranking of journals in JCR categories. The objectives of this study were to empirically evaluate the effect of increases in citations on the computation of the journal impact factor (JIF) for a large set of journals as measured by changes in JIF, and to ascertain the influence of additional citations on the rank order of journals according their new JIFs within JCR groups. To do so, modified JIFs were computed by adding additional citations to the number used by Thomson-Reuters to compute the JIF of journals listed in the JCR for 2008. We considered the effect on rank order of a given journal of adding 1, 2, 3 or more citations to the number used to compute the JIF, keeping everything else equal (i.e., without changing the JIF of other journals in a given group). The effect of additional citations on the internal structure of rankings in JCR groups increased with the number of citations added. In about one third of JCR groups, about half the journals changed their rank order when 1–5 citations were added. However, in general the rank order tended to be relatively stable after small increases in citations.     

Citation mechanics in Journals covered by the journal citation reports

Citations from 1980 to 1988, obtained from fifty biomedical journals covered by theJournal Citation Reports (JCR) are studied. In purely numerical terms, the evolution of each citation (journal citation), including its impact factor (IF), would depend essentially on three variables for each journal: (i) the yearly rate of increase of items that could be cited (citable items), (ii) the relative yearly increment of the citing journals, (iii) the relative yearly increment of citations. The mechanics of this give rise to the three standard patterns for journal citations, namely: (i) annual impact factors increase each year (ascending evolution), (ii) annual impact factors remain the same each year (constant evolution), (iii) annual impact factors decrease each year (descending evolution). The reason why some journal citation profiles do not fit into the standard patterns is presumably that forces are at work able to alter the numerical mechanics described. The concepts of saturation/unsaturation of the demand for scientific information are introduced, showing how they are reflected in the impact factor figures for the journals cited.     

Journal report card

The impact factor is one of the most used scientometric indicators. Its proper and improper uses have been discussed extensively before. It has been criticized extensively, yet it is still here. In this paper I propose the journal report card, which is a set of measures, each with an easily comprehensible meaning that provides a fuller picture of the journals?? standing. The set of measures in the report card include the impact factor, the h-index, number of citations at different points on the ranked list of citations, extent of uncitedness and coverage of the h-core. The report card is computed for two sets of journals, the top-20 journals in JCR 2010 and the top-20 journals in JCR 2010 for the category Information and Library Science.     

The SCI Journal Citation Reports: A potential tool for studying journals?

In this paper, we analysed six indicators of the SCI Journal Citation Reports (JCR) over a 19-year period: number of total citations, number of citations to the two previous years, number of source items, impact factor, immediacy index and cited half-life. The JCR seems to have become more or less an authority for evaluating scientific and technical journals, essentially through its impact factor. However it is difficult to find one's way about in the impressive mass of quantitative data that JCR provides each year. We proposed the box plot method to aggregate the values of each indicator so as to obtain, at a glance, portrayals of the JCR population from 1974 to 1993. These images reflected the distribution of the journals into 4 groups designated low, central, high and extreme. The limits of the groups became a reference system with which, for example, it was rapidly possible to situate visually a given journal within the overall JCR population. Moreover, the box plot method, which gives a zoom effect, made it possible to visualize a large sub-population of the JCR usually overshadowed by the journals at the top of the rankings. These top level journals implicitly play the role of reference in evaluation processes. This often incites categorical judgements when the journals to be evaluated are not part of the top level. Our «rereading» of the JCR, which presented the JCR product differently, made it possible to qualify these judgements and bring a new light on journals.     

The self-cited rate of scientific journals and the manipulation of their impact factors

Owing to some discussions about manipulating impact factor by requesting authors to increase their citations to the publication journal, we theoretically establish a mathematical expression of a relation between the journal self-citation rate and its impact factor by the single-factor method in this paper. Based on self-citation data of some journals in JCR and the observed relation between journal impact factor and the self-cited rate, we analyze the possibility that journal editors manipulate impact factors of their journals by raising the self-cited rate. Finally, we make some suggestions for supervising this crude way of active manipulating the impact factor.     

Effect on the journal impact factor of the number and document type of citing records: a wide-scale study

We studied the effect on journal impact factors (JIF) of citations from documents labeled as articles and reviews (usually peer reviewed) versus citations coming from other documents. In addition, we studied the effect on JIF of the number of citing records. This number is usually different from the number of citations. We selected a set of 700 journals indexed in the SCI section of JCR that receive a low number of citations. The reason for this choice is that in these instances some citations may have a greater impact on the JIF than in more highly-cited journals. After excluding some journals for different reasons, our sample consisted of 674 journals. We obtained data on citations that contributed to the JIF for the years 1998?C2006. In general, we found that most journals obtained citations that contribute to the impact factor from documents labeled as articles and reviews. In addition, in most of journals the ratio between citations that contributed to the impact factor and citing records was greater than 80% in all years. Thus, in general, we did not find evidence that citations that contributed to the impact factor were dependent on non-peer reviewed documents or only a few citing records.     

An examination of “citation circles” for social sciences journals in Eastern European countries

This study aims to explore the effects of both journal self citations and mutual citations within a group of journals on the increase in the impact factors (IFs) for social sciences journals published in Eastern Europe. We found that the practice of mutual citations is prevalent among the new journals, a trend that raises questions about possible manipulation of the IF and potential isolation of the recent journals from the international network of scholarly communication.     

A New Approach to the SCI Journal Citation Reports,a System for Evaluating Scientific Journals

The Science Citation Index, Journal Citation Reports (JCR), published by the Institute for Scientific Information (ISI) and designed to rank, evaluate, categorize and compare journals, is used in a wide scientific context as a tool for evaluating researchers and research work, through the use of just one of its indicators, the impact factor. With the aim of obtaining an overall and synthetic perspective of impact factor values, we studied the frequency distributions of this indicator using the box-plot method. Using this method we divided the journals listed in the JCR into five groups (low, lower central, upper central, high and extreme). These groups position the journal in relation to its competitors. Thus, the group designated as extreme contains the journals with high impact factors which are deemed to be prestigious by the scientific community. We used the JCR data from 1996 to determine these groups, firstly for all subject categories combined (all 4779 journals) and then for each of the 183 ISI subject categories. We then substituted the indicator value for each journal by the name of the group in which it was classified. The journal group may differ from one subject category to another. In this article, we present a guide for evaluating journals constructed as described above. It provides a comprehensive and synthetic view of two of the most used sections of the JCR. It makes it possible to make more accurate and complete judgements on and through the journals, and avoids an oversimplified view of the complex reality of the world of journals. It immediately reveals the scientific subject category where the journal is best positioned. Also, whereas it used to be difficult to make intra- and interdisciplinary comparisons, this is now possible without having to consult the different sections of the JCR. We construct this guide each year using indicators published in the JCR by the ISI.     

The nature and relationship between the productivity of journals and their citations in semiconductor literature

The purpose of this study was to investigate the relationship between journals" productivity and their citations in the field of semiconductors. Journal samples were gathered from the INSPEC database, 1978 to 1997 while the data of citation frequency, impact factor, cited half-life and citing half-life were obtained from Science Citation Index, Journal Citation Reports 1997 CD-ROM edition. One thousand and eight hundred and seventy seven journals publishing articles on semiconductors were retrieved. The nature for the data of journal productivity, impact factor, cited half-life and citing half-life are explored. Among these journals, only 672 journals that were covered in JCR were compared. Moreover, statistical tests of more productive journals with cumulative publication in semiconductor >100 were also conducted on the basis of all articles they published annually (for 1997). The results of the study showed that there is a significant correlation between journal productivity and citation frequency and between journal productivity and impact factor. However, there are no associations between journal productivity and cited half-life and between journal productivity and citing half-life. This revised version was published online in August 2006 with corrections to the Cover Date.     

The visibility of Italian journals

The main purpose of this study was to analyze the Italian journals indexed in the 2000 edition of the Journal Citation Reports (JCR) published by the Institute for Scientific Information (ISI) (Philadelphia, USA). The performance and the visibility of these journals were evaluated in terms of Impact Factor (IF), mean IF from citing journals and cited journals, and self-citing and self-cited rates. Seventy-three Italian journals were indexed in the JCR, 14 of which achieved an IF equal to or higher than one. Most citing journals were European and American, thus showing a fairly good visibility of the articles published in the 14 journals analyzed. The self-citing and self-cited rates showed a wide variation. The journal that appeared to perform best was theJournal of High Energy Physics, an electronic publication whose success seemingly confirms Internet circulation as an effective means to enhance the visibility and consequently the quality, in term of citations, of a journal. Italy's low overall expenditure on research & development (R&D) and low number of researchers compared to countries with longstanding high publishing standards and traditions are no doubt partly to blame for its poor performance in scientific publishing. This revised version was published online in August 2006 with corrections to the Cover Date.     

Some considerations on the use of the impact factor of scientific journals as a tool to evaluate research in psychology

Summary This paper identifies and presents some characteristics of the psychology journals included in each of the Journal Citation Reports (JCR) categories in 2002. The study shows that most of the journals belong to the categories of Multidisciplinary Psychology (102) and Clinical Psychology (83). Their ranking is seen to vary depending on the category, and the same journal may occupy different positions in different JCR categories. Journals included in the categories of Biological Psychology, Experimental Psychology and Multidisciplinary Psychology had the highest impact factor (IF).     

Disciplinarity and interdisciplinarity in citation and reference dimensions: knowledge importation and exportation taxonomy of journals

This work proposes an entropy-based disciplinarity indicator (EBDI) which allows the classification of scientific journals in four classes: knowledge importer, knowledge exporter, disciplinary and interdisciplinary with regards to the discipline(s) in which they are classified. Assuming that the set references in the papers published in a journal represent a significant part of their knowledge basis, the diversity (measured with Shannon’s entropy) and ratio between internal and external (to the discipline in which the journal is classified) references can provide a measure of the disciplinarity/interdisciplinarity of the journal in the reference dimension. The homologous analysis can be applied to the set of citations received by the papers published in the journal. In this article, an entropy-based indicator for the measurement of the disciplinarity of scientific journals is developed, applied (to the cited and citing dimensions) and discussed. The indicator can take finite values and it is found to be theoretically consistent when tested against two definitions for bibliometric indicators. The combinations of disciplinarity values in the citing and cited dimensions permits the classification of journals according to their knowledge importing/exporting profile (separately, with regards to the social sciences or the sciences), providing a taxonomy of the role of journals according to their importing, exporting, interdisciplinary or specialized profile with regards to the subject category in which they are classified. The indicator, EBDI and the resulting taxonomy is proposed and tested for the set of journals in LIS subject category in JCR 2013 and for the sets of journals in Andrology and Legal Medicine in JCR 2015. Evidence of concurrent validity with journal co-classification patterns is found in the three sets of journals.     

The impact of internet resources on scholarly communication: A citation analysis

The quality and credibility of Internet resources has been a concern in scholarly communication. This paper reports a quantitative analysis of the use of Internet resources in journal articles and addresses the concerns for the use of Internet resources scholarly journals articles. We collected the references listed in 35,698 articles from 14 journals published during 1996 to 2005, which resulted in 1,000,724 citations. The citation data was divided into two groups: traditional citations and Web citations, and examined based on frequencies of occurrences by domain and type of Web citation sources. The findings included: (1) The number of Web citations in the journals investigated had been increasing steadily, though the quantity was too small to draw an inclusive conclusion on the data about their impact on scientific research; (2) A great disparity existed among different disciplines in terms of using information on the Web. Applied disciplines and interdisciplinary sciences tended to cite more information on the Web, while classical and experimental disciplines cited little of Web information; (3) The frequency of citations was related to the reputation of the author or the institution issuing the information, and not to the domain or webpage types; and (4) The researchers seemed to lack confidence in Internet resources, and Web information was not as frequently cited as reported in some publications before. The paper also discusses the need for developing a guideline system to evaluate Web resources regarding their authority and quality that lies in the core of credibility of Web information.     

The matthew index—Concentration patterns and Matthew core journals

In this paper we extend our studies to the micro-structure of the Matthew effect for countries (MEC). The MEC allows the ranking of countries by their Matthew Index. The rank distribution of countries, observable only at a macro-level, has its roots in re-distribution processes of citations in every journal of the database. These re-distributed citations we call Matthew citations. Data for 44 countries and 2712 journals (based on theScience Citation Index) are analyzed. The strength of the contribution of the individual journals to the MEC (their number of Matthew citations) is skewly distributed. Due to this high concentration of the MEC we are able to define a new type of journal the Matthew core journal: 145 Matthew core journals account for 50% of the MEC. These journals carry a high potential of gaining a surplus of citations over what is expected and the risk of losing a high number of citations as well.     

The citation impacts and citation environments of Chinese journals in mathematics

Based on the citation data of journals covered by the China Scientific and Technical Papers and Citations Database (CSTPCD), we obtained aggregated journal-journal citation environments by applying routines developed specifically for this purpose. Local citation impact of journals is defined as the share of the total citations in a local citation environment, which is expressed as a ratio and can be visualized by the size of the nodes. The vertical size of the nodes varies proportionally to a journal’s total citation share, while the horizontal size of the nodes is used to provide citation information after correction for the within-journal (self-) citations. In the “citing” environment, the equivalent of the local citation performance can also be considered as a citation activity index. Using the “citing” patterns as variables one is able to map how the relevant journal environments are perceived by the collective of authors of a journal, while the “cited” environment reflects the impact of journals in a local environment. In this study, we analyze citation impacts of three Chinese journals in mathematics and compare local citation impacts with impact factors. Local citation impacts reflect a journal’s status and function better than (global) impact factors. We also found that authors in Chinese journals prefer international instead of domestic ones as sources for their citations.     

Motivations for URL citations to open access library and information science articles

Summary We define the URL citations of a Web page to be the mentions of its URL in the text of other Web pages, whether hyperlinked or not. The proportions of formal and informal scholarly motivations for creating URL citations to Library and Information Science open access journal articles were identified. Five characteristics for each source of URL citations equivalent to formal citations were manually extracted and the relationship between Web and conventional citation counts at the e-journal level was examined. Results of Google searches showed that 282 research articles published in the year 2000 in 15 peer-reviewed LIS open access journals were invoked by 3,045 URL citations. Of these URL citations, 43% were created for formal scholarly reasons equivalent to traditional citations and 18% for informal scholarly reasons. Of the sources of URL citations, 82% were in English, 88% were full text papers and 58% were non-HTML documents. Of the URL citations, 60% were text URLs only and 40% were hyperlinked. About 50% of URL citations were created within one year after the publication of the cited e-article. A slight correlation was found between average numbers of URL citations and average numbers of ISI citations for the journals in 2000. Separating out the citing HTML and non-HTML documents showed that formal scholarly communication trends on the Web were mainly influenced by text URL citations from non-HTML documents.     

Competition in science and the Matthew core journals

Competition is one of the most essential features of science. A new journal indicator - the"number of Matthew citations in a journal" was found that reflects certain aspects of thiscompetition. The indicator mirrors the competition of countries in scientific journals forrecognition in terms of seemingly "redistributed" citations.The indicator shows, as do other journal indicators, an extreme skewed distribution over anensemble of 2712 SCI journals. Half of all Matthew citations are contained in 144 so-calledMatthew core journals.In this paper, a new typology of scientific journals, including the Matthew core journals, isintroduced. For a few selected journals, graphs are presented showing national impact factors aswell as the absolute number of Matthew citations gained or lost by the countries publishing in thejournal.Scientific competition among countries for recognition is strongest in the Matthew corejournals, they are the most competitive markets for scientific publications. Conclusions are drawnfor national science policy, for the journal acquisition policy of national libraries, and for thepublication behaviour of individual scientists.     

Journal impact evaluation: a webometric perspective

In theory, the web has the potential to provide information about the wider impact of academic research, beyond traditional scholarly impact. This is because the web can reflect non-scholarly uses of research, such as in online government documents, press coverage or public discussions. Nevertheless, there are practical problems with creating metrics for journals based on web data: principally that most such metrics should be easy for journal editors or publishers to manipulate. Nevertheless, two alternatives seem to have both promise and value: citations derived from digitised books and download counts for journals within specific delivery platforms.     

On the impact of Gold Open Access journals

Gold Open Access (=Open Access publishing) is for many the preferred route to achieve unrestricted and immediate access to research output. However, true Gold Open Access journals are still outnumbered by traditional journals. Moreover availability of Gold OA journals differs from discipline to discipline and often leaves scientists concerned about the impact of these existent titles. This study identified the current set of Gold Open Access journals featuring a Journal Impact Factor (JIF) by means of Ulrichsweb, Directory of Open Access Journals and Journal Citation Reports (JCR). The results were analyzed regarding disciplines, countries, quartiles of the JIF distribution in JCR and publishers. Furthermore the temporal impact evolution was studied for a Top 50 titles list (according to JIF) by means of Journal Impact Factor, SJR and SNIP in the time interval 2000–2010. The identified top Gold Open Access journals proved to be well-established and their impact is generally increasing for all the analyzed indicators. The majority of JCR-indexed OA journals can be assigned to Life Sciences and Medicine. The success-rate for JCR inclusion differs from country to country and is often inversely proportional to the number of national OA journal titles. Compiling a list of JCR-indexed OA journals is a cumbersome task that can only be achieved with non-Thomson Reuters data sources. A corresponding automated feature to produce current lists “on the fly” would be desirable in JCR in order to conveniently track the impact evolution of Gold OA journals.