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.     

Journal co-citation analysis of semiconductor literature

The purpose of this study is to map semiconductor literature using journal co-citation analysis. The journal sample was gathered from the INSPEC database from 1978 to 1997. In the co-citation analysis, the data compiled were counts of the number of times two journal titles were jointly cited in later publications. It is assumed that the more two journals are cited together, the closer the relationship between them. The journal set used was the 30 most productive journals in the field of semiconductors. Counts of co-citations to the set of semiconductor journals were retrieved from SciSearch database, accessed through Dialog. Cluster analysis and multi-dimensional scaling were employed to create two-dimensional maps of journal relationships in the cross-citation networks. The following results were obtained through this co-citation study: The 30 journals fall fairly clearly into three clusters. The major cluster of journals, containing 17 titles, is in the subject of physics. The second cluster, consisting of 9 journals, includes journals primarily on material science. The remaining cluster represents research areas in the discipline of electrical and electronic engineering. All co-cited journals share similar co-citation profiles, reflected in high positive Pearson correlation. Two hundred and ninety-six pairs (68%) correlate at greater than 0.70. This shows that there is strong relationship between semiconductor journals. Five individual journals in five paired sets with co-citation frequency over 100,000 times include Physical Review B, Condensed Matter; Physical Review Letters; Applied Physics Letters; Journal of Applied Physics; and Solid State Communications. This revised version was published online in August 2006 with corrections to the Cover Date.     

Towards appropriate indicators of journal impact

This paper reviews a range of studies conducted by the authors on indicators reflecting scholarly journal impact. A critical examination of the journal impact data in theJournal Citation Reports (JCR), published by the Institute for Scientific Information (ISI) has shown that the JCR impact factor is inaccurate and biased towards journals revealing a rapid maturing or decline in impact. In addition, it was found that the JCR cited half life is an inappropriate measure of decline of journal impact. More appropriate impact measures of scholarly journals are proposed. A new classification system is explored, describing both maturing and decline of journal impact as measured through citations. Suggestions for future research are made, analysing in more detail the distribution of citations among papers in a journal.     

Comparative indicators of interdisciplinarity in modern science

A set of scientometric indicators of interdisciplinary links between advancing fields of biomedicine is suggested. Twenty jounals listed in theJCR of theSCI for 1988 are analyzed. An index of interdisciplinarity for a given journal is calculated as the sum of ratios between the numbers of journals from all other disciplines (except for general-scientific and miscellaneous journals) and from the same discipline cited by that journal or citing it, and of ratios between the numbers of citations to and by these journals. Some interdisciplinary patterns of 20 andrology journal articles are scientometrically assessed, too. The combined usage of this method with co-classification and co-citation methodology can optimize interdisciplinarity evaluation and promotion.     

The growth of biophysical literature

The enormous growth of biophysical literature has created great difficulties in tracking out the significant literature of the subject. To cope with this unprecedented growth of literature, a new bibliometric technique has been applied to rank periodicals in the field based on 4228 citation data collected from the bibliographic data base published in the source journal namely,Annual Review of Biophysics. This list is expected to reflect the impact of literature on the advancement of knowledge in the field of biophysics. A striking feature of the ranking list is the high positions occupied by multidisciplinary science journals and biochemical journals as compared to journals exclusively and specifically devoted to biophysics or any particular aspects of it. Other remarkable findings are the wide scatter of biophysics literature; dominance of the USA journals and status attained by English as the preferred medium of communications of the working biophysicists. The data are also analysed according to subject categorization of the ranked periodicals. The results of the present study have been discussed in relation to Bradford's Law of Scattering and validity of the extension of the law, suggested earlier, has been well established. It is expected that the present ranking list will enable the working biophysicists to select journals from the viewpoint of their significance to the active areas of present-day biophysical research.     

Empirical series of journal h-indices: The JCR category Horticulture as a case study

Two types of series of h-indices for journals published in the field of Horticulture during the period 1998–2007 are calculated. Type I h-indices are based on yearly data, while type II h-indices use cumulative data. These h-indices are also considered in a form normalised with respect to the number of published articles. It is observed that type I h-indices, normalised or not, decrease linearly over a period of ten years. The type II series, however, is not linear in nature: it exhibits partly a concave shape. This proves that the journals (in Horticulture) do not exhibit a linear increase in h-index as argued by Hirsch in the case of life-time achievements of scientists. In the second part of the paper, an attempt is made to study the relative visibility of a journal and its change over time, based on h-indices of journals. It is shown that:

The journal relative impact: an indicator for journal assessment

This paper presents the journal relative impact (JRI), an indicator for scientific evaluation of journals. The JRI considers in its calculation the different culture of citations presented by the Web of Science subject categories. The JRI is calculated considering a variable citation window. This citation window is defined taking into account the time required by each subject category for the maturation of citations. The type of document considered in each subject category depends on its outputs in relation to the citations. The scientific performance of each journal in relation to each subject category that it belongs to is considered allowing the comparison of the scientific performance of journals from different fields. The results obtained show that the JRI can be used for the assessment of the scientific performance of a given journal and that the SJR and SNIP should be used to complement the information provided by the JRI. The JRI presents good features as stability over time and predictability.     

Improving SCImago Journal &; Country Rank (SJR) subject classification through reference analysis

In order to re-categorize the SCImago Journal & Country Rank (SJR) journals based on Scopus, as well as improve the SJR subject classification scheme, an iterative process built upon reference analysis of citing journals was designed. The first step entailed construction of a matrix containing citing journals and cited categories obtained through the aggregation of cited journals. Assuming that the most representative categories in each journal would be represented by the highest citation values regarding categories, the matrix vectors were reduced using a threshold to discern and discard the weakest relations. The process was refined on the basis of different parameters of a heuristic nature, including (1) the development of several tests applying different thresholds, (2) the designation of a cutoff, (3) the number of iterations to execute, and (4) a manual review operation of a certain amount of multi-categorized journals. Despite certain shortcomings related with journal classification, the method showed a solid performance in grouping journals at a level higher than categories—that is, aggregating journals into subject areas. It also enabled us to redesign the SJR classification scheme, providing for a more cohesive one that covers a good proportion of re-categorized journals.     

Commercial scientific journals and their editors in Edinburgh, 1819–1832

This paper explores the editorial policies and practices of three scientific journal published in Edinburgh in the first half of the 19th century. The first of these was the Edinburgh Philosophical Journal (1819–1826), and its continuation as the Edinburgh New Philosophical Journal (1826–1854). It was edited until 1824 by Robert Jameson, Edinburgh's professor of natural history, and David Brewster, who was a natural philosopher, scientific writer, and editor. Brewster left in 1824 to found his own journal, the Edinburgh Journal of Science (1824–1832). The third journal published in Edinburgh in this period was the Edinburgh Journal of Natural and Geographical Science (1829–1831), edited by Henry H. Cheek and William Ainsworth, two medical students at the University of Edinburgh. All three journals were direct competitors, being strikingly similar in form and content. As well as competing with Jameson's journal for readers and authors, Cheek and Ainsworth also used their journal to directly attack him in print. This paper sheds new light on the ways the editorship of these journals was used not only to consolidate and extend circles of patronage in early 19th-century science, but also to challenge existing centres of authority.     

Correlation between the Journal Impact Factor and three other journal citation indices

To determine the degree of correlation among journal citation indices that reflect the average number of citations per article, the most recent journal ratings were downloaded from the websites publishing four journal citation indices: the Institute of Scientific Information’s journal impact factor index, Eigenfactor’s article influence index, SCImago’s journal rank index and Scopus’ trend line index. Correlations were determined for each pair of indices, using ratings from all journals that could be identified as having been rated on both indices. Correlations between the six possible pairings of the four indices were tested with Spearman’s rho. Within each of the six possible pairings, the prevalence of identifiable errors was examined in a random selection of 10 journals and among the 10 most discordantly ranked journals on the two indices. The number of journals that could be matched within each pair of indices ranged from 1,857 to 6,508. Paired ratings for all journals showed strong to very strong correlations, with Spearman’s rho values ranging from 0.61 to 0.89, all p < 0.001. Identifiable errors were more common among scores for journals that had very discordant ranks on a pair of indices. These four journal citation indices were significantly correlated, providing evidence of convergent validity (i.e. they reflect the same underlying construct of average citability per article in a journal). Discordance in the ranking of a journal on two indices was in some cases due to an error in one index.     

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.     

An impact of Croatian journals measured by citation analysis from SCI-expanded database in time span 1975–2001

The aim of this research is to gain an insight into international recognition of the STM (Science, Technology, and Medicine) Croatian journals measured by citations in SCI-expanded database. The sample for the research was a citation analysis of 142 journals in time span 1975–2001 for papers published in 1975–1998. More than 90% of those journals are not indexed by SCI-expanded. For the purpose of this research we introduced a new scientometric indicator Normalized number of Citations per 100 Papers (NCP) that allows us direct comparison of the journals from various categories (NCP = 100C/P / IF₁₉₈₉). We chose the year 1989 as a mean value for time span 1975–2001. By citation analysis we established the influence of errors on recognition of Croatian journals and their articles. Obtained results show that an article-to-article link is not found for 32% of cited items. The most frequent type of error is journal title, 37%, which indicates that approximately one third of Croatian journals can not be found when searching by journal title only. Some Croatian journals, even not indexed by SCI-expanded, showed relatively high rank in an impact, i.e. their NCP is higher than 100, and number of citations per paper is higher than 1.     

A new reference standard for citation analysis in chemistry and related fields based on the sections of <Emphasis Type="Italic">Chemical Abstracts</Emphasis>

Citation analysis for evaluative purposes requires reference standards, as publication activity and citation habits differ considerably among fields. Reference standards based on journal classification schemes are fraught with problems in the case of multidisciplinary and general journals and are limited with respect to their resolution of fields. To overcome these shortcomings of journal classification schemes, we propose a new reference standard for chemistry and related fields that is based on the sections of the Chemical Abstracts database. We determined the values of the reference standard for research articles published in 2000 in the biochemistry sections of Chemical Abstracts as an example. The results show that citation habits vary extensively not only between fields but also within fields. Overall, the sections of Chemical Abstracts seem to be a promising basis for reference standards in chemistry and related fields for four reasons: (1) The wider coverage of the pertinent literature, (2) the quality of indexing, (3) the assignment of papers published in multidisciplinary and general journals to their respective fields, and (4) the resolution of fields on a lower level (e.g. mammalian biochemistry) than in journal classification schemes (e.g. biochemistry & molecular biology).     

Citedness and uncitedness of cancer articles

There is a rapid growth of cancer literature. Thousands of papers are being regularly published every year not only in speciality journals, but also in journals of other disciplines. Citation studies are nowadays considered a major basis of science indicators for ascertaining the importance of a scientific journal and that of the published articles on a particular subject. In oncological research the journalCancer is considered as one of the top most journals and is universally well known for its high standard and excellence. In this paper an attempt has been made to find out the importance of all the articles published in it for a particular year. Side by side bibliometric analysis was made to ascertain various other aspects like time lag between publication and first citation of articles, average citation time, subject scattering and identification of most important journals in the field etc. It is believed that this study would be of help to the working oncologists, librarians and information scientists to assess the importance of articles published in a top ranking journal of cancer and also that of different journals publishing oncological research results.     

Equal contributions and credit given to authors in anesthesiology journals during a 10-year period

To investigate the prevalence and characteristics of the practice of explicitly giving authors equal credit in publications of major anesthesiology journals. Four major anesthesiology journals (Anesthesia and Analgesia (AA), Anesthesiology, British Journal of Anaesthesia (BJA) and Pain) were searched manually to identify original research articles published between January 1st, 2001 and December 31st, 2010 with respect to equally credited authors (ECAs). It was found that all journals explicitly gave authors equal credit, and articles with ECAs accounted for a greater proportion of the total number of articles published in each journal in 2010 versus that in 2000 (AA: 3.3% vs. 0%; Anesthesiology: 7.1% vs. <1%; BJA: 5.7% vs. 0%; Pain: 11.0% vs. <1%). The number of ECAs articles tended to increase significantly yearly in all journals (P < 0.0001 for each journal). The first two authors in the byline received equal credit in most cases. Furthermore, the ECAs articles involved institutions from different countries and regions and were sponsored by various funds. However, no specific guidance concerning this practice was provided in the instructions to authors in the four journals. It is increasingly common to give authors equal credit in original research articles in major anesthesiology journals. Detailed guidelines regarding this practice are warranted in future.     

Article-count impact factor of materials science journals in SCI database

This article proposed a new index, so-called “Article-Count Impact Factor” (ACIF) for evaluating journal quality in light of citation behaviour in comparison with the ISI journal impact factors. The ACIF index was the ratio of the number of articles that were cited in the current year to the source items published in that journal during the previous two years. In this work, we used 171 journal titles in materials categories published in the years of 2001–2004 in international journals indexed in the Science Citation Index Expanded (SCI) database as data source. It was found that ACIF index could be used as an alternative tool in assessing the journal quality, particularly in the case where the assessed journals had the same (equal or similar) JIF values. The experimental results suggested that the higher the ACIF value, the more the number of articles being cited. The changes in ACIF values were more dependent on the JIF values rather than the total number of articles. Polymer Science had the greatest ACIF values, suggesting that the articles in Polymer Science had greater “citation per article” than those in Metallurgical Engineering and Ceramics. It was also suggested that in order to increase a JIF value of 1.000, Ceramics category required more articles to be cited as compared to Metallurgical Engineering and Polymer Science categories.     

The delineation of specialties in terms of journals using the dynamic journal set of the SCI

In order to attribute journals to specialties in a dynamic journal set by using aggregated journal-journal citations derived from theScience Citation Index, it is necessary to complement the multi-variate analysis of this data with a time-serices perspective. This calls for a more analytical approach to the problem of choice among the many possible parameters for clustering. Changes in the disciplinary structure of science are tracked by using thedifferences among the multi-variate analyses for the various years. It is impossible to attribute change systematically to structure, noise, or deviance if these uncertainties are not clearly definedex ante. The study discusses the various choices which have to be made, in both conceptual and methodological terms. In addition to hierarchies among journals, one has to assume heterarchy among journal groups (and their centroids). For comprehensive mapping, a concept of macro-journals as representations of a density of points in the multi-dimensinoal space is defined. Empirical reslts indicate the feasibility of dynamic journal-journal mapping by using these methods.     

The authorship and internationality of Industrial Engineering journals

This paper surveys 32 renowned Industrial Engineering (IE) journals with regard to authorship for the period of 1996–2005. The findings show that the USA was the top contributing country, accounting for approximately one-third of the total number of articles. The 80/20 rule and the entropy measure consistently identify Issues in Science and Technology (IST), Industrial Engineer (IE), and R&D Magazine (RDM) as journals of high country concentration, or journals of low internationality. Conversely, Journal of Materials Processing Technology (JMPT), Production Planning & Control (PPC), and Technovation (TNV) have the highest degree of country diversity, or internationality. The quality of a journal, as expressed by impact factors, its internationality, and its number of articles published, are found to be independent of each other.     

Citation analysis and peer ranking of Australian social science journals

Citation analyses were performed for Australian social science journals to determine the differences between data drawn from Web of Science and Scopus. These data were compared with the tier rankings assigned by disciplinary groups to the journals for the purposes of a new research assessment model, Excellence in Research for Australia (ERA), due to be implemented in 2010. In addition, citation-based indicators including an extended journal impact factor, the h-index, and a modified journal diffusion factor, were calculated to assess whether subsequent analyses influence the ranking of journals. The findings suggest that the Scopus database provides higher number of citations for more of the journals. However, there appears to be very little association between the assigned tier ranking of journals and their rank derived from citations data. The implications for Australian social science researchers are discussed in relation to the use of citation analysis in the ERA.