Journals of general &; internal medicine and surgery: An analysis and comparison of citation

Summary The purpose of this study is to analyze and compare journal citation data, from Journal Citation Reports on the Web 2000, of general and internal medicine and surgery. The source items and five kinds of citation data, i.e. citation counts, impact factor, immediacy index, citing half-life and cited half-life are examined and the correlation between each of the fifteen pairs of citation data is determined based on the Pearson correlation tests. The Fishers Z-transform was employed to test the significant difference between the Pearson correlation coefficient for each pair of citation data of these two subject areas. The following results of this work reveal: the frequently published journals are cited more frequently and also with high impact factor and immediacy index, in addition, they are usually accompanied with short citing half-life (i.e., usually cite current literature). The impact factor and immediacy index has significant correlation with citation counts. A significant correlation also exists between impact factor and immediacy index. However there is no correlation between cited half-life and other citation data, except citing half-life. For journals of general and internal medicine and surgical medicine, there are no significant difference of the Pearson correlation coefficient for the following pair of citation data: source items and citation counts, source items and impact factor, source items and citing half-life, citation counts and citing half-life, impact factor and citing half-life, immediacy index and citing half-life, and cited half-life and citing half-life.     

A quantitative exploration on reasons for citing articles from the perspective of cited authors

Citation is regarded as one of the “norms of science” (Merton in Am Sociol Rev 22(6):635–659, 1957) and is deeply researched by the field of scientometrics. The motivations authors have for citing one another are considered significant and have been the subject of extensive qualitative research such as content analysis, questionnaires, and interviews of citing authors. However, the existing qualitative studies have covered a limited number of samples. To expand the dataset, this paper proposes a quantitative method applied to detecting citation reasons from the angle of citation networks and the attributes of cited authors, including their publication count (the number of single-authored publications, collaborative and first-authored publications as well as collaborative but non-first-authored publications, and number of whole publications), citation count, research topic interests, and gender. By applying the Exponential Random Graph Models (ERGMs), the current study revealed that authors in the field of information retrieval tend to cite those with more single-authored, collaborative and first-authored, and collaborative but not first-authored publications. Besides, in this field, the number of publications, similar topical domains, and same gender are proven to be significantly favorable in selecting references in our experiment.     

Citation frequency: A biased measure of research impact significantly influenced by the geographical origin of research articles

Context. The use of citation frequency and impact factor as measures of research quality and journal prestige is being criticized. Citation frequency is augmented by self-citation and for most journals the majority of citations originate from a minority of papers. We hypothesized that citation frequency is also associated with the geographical origin of the research publication. Objective. We determined whether citations originate more frequently from institutes that are located in the same country as the authors of the cited publication than would be expected by chance. Design. We screened citations referring to 1200 cardiovascular publications in the 7 years following their publication. For the 1200 citation recipient publications we documented the country where the research originated (9 countries/regions) and the total number of received citations. For a selection of 8864 citation donor papers we registered the country/region where the citing paper originated. Results. Self-citation was common in cardiovascular journals (n = 1534, 17.8%). After exclusion of self-citation, however, the number of citations that originated from the same country as the author of the citation recipient was found to be on average 31.6% higher than would be expected by chance (p<0.01 for all countries/regions). In absolute numbers, nation oriented citation bias was most pronounced in the USA, the country with the largest research output (p<0.001). Conclusion. Citation frequency was significantly augmented by nation oriented citation bias. This nation oriented citation behaviour seems to mainly influence the cumulative citation number for papers originating from the countries with a larger research output.     

A study on the citation situation within the citing paper: citation distribution of references according to mention frequency

Citation impact indicators play a significant role in evaluating the scientific research activity. Most of citation impact indicators are based on the citation count that the publication is cited as a reference in the other publications, but the difference between each citation situation was not considered. Normally, the number of citations that a publication is cited in the other publications may represent the formal quality of the publication. Similarly, the number of times that a publication is really mentioned within the citing publication, it may also represent the formal quality of the citation. We have examined about how many times each reference was really mentioned within the citing publications and studied about the citation situation within the citing publications. We verified that the citation distribution of references according to the mention frequency follows the Generalized Pareto distribution. The results showed that about 20% of total references were mentioned three and more times, and the number of citation mentions for the about 50% of total references were from about 20% of the total references in the citing publications.     

Are methodological papers more cited than theoretical or empirical ones? The case of sociology

The objective of this study is to find out whether methodological papers published in core sociological journals are more frequently cited than theoretical or empirical (substantive) papers. The results indicate that such is indeed the case; moreover, this result is not due to a few outlying, very highly cited papers. These findings are based on all the methodological and theoretical papers, and a sample of the empirical papers, published in 1972 and 1973 in three high-impact sociological journals. The citation counts for these papers were compiled from theSocial Science Citation Index for the years 1972–1981. The data were analyzed separately for each journal and year of publication.     

A quasi-quantitative citation model

On the basis of investigating author's opinion on citing motivations of chemistry papers aquasi-quantitative model for citing is suggested. The model selects professional and nonprofessional motivations of citing and introduces thecitation threshold concept which tries to characterize the effect of citing motivations quantitatively. Possible reasons for missing citations are also treated. Mean ages of real and of self-citations were calculated by subtracting the average of the publication years of cited papers from the publication year of the citing publication. The difference between the mean ages may characterize thesynchronity of the author's research in comparison with those working on similar topics. The paper introduces thecitation strategy indicator which relates impact factors of cited periodicals with the mean impact factor of periodicals in the corresponding research subfield.     

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.     

Reference standards for citation based assessments

One of the most crucial points of citation-based assessments is to find proper reference standards to which the otherwise meaningless plain citation counts can be compared. Using such standards, mere absolute numbers can be turned into relative indicators, suitable for cross-national and cross-field comparisons. In the present study, three possible choice of reference standards for citation assessments are discussed. Citation rates of publications under study can be compared to the average citation rates of the papers of the publishing journals to result inRelative Citation Rate (RCR), an indicator successfully used in several comparative scientometric analyses (see, e.g. Refs 1–5). A more customized reference set is defined by therelated records in the new CD Edition of theScience Citation Index database. Using the socalled bibliographic coupling technique, a set of papers with a high measure of similarity in their list of references is assigned to every single paper of the database. Beside of being an excellent retrieval tool, related records provide a suitable reference set to assess the relative standing of a given set of papers as measured by citation indicators. The third choice introduced in this study is specifically designed for assessing journals. For this purpose, the set of journals cited by the journal in question seems to be a useful basis to compare with. The pros and cons of the three choices are discussed and several examples are given.     

Using ISI's 'Highly Cited Researchers' to obtain a country level indicator of citation excellence

Summary A high level of citation to an author's work is, in general, a testimony to the fact that the author's work has been noted and used by his peers. High citation is seen to be correlated with other forms of recognition and rewards, and is a key indicator of research performance, among other bibliometric indicators. The Institute for Scientific Information (ISI) defines a 'highly cited researcher' (HCR) as one of 250 most cited authors of journal papers in any discipline. Citation data for 20 years (1981-1999) is used to calculate the share of HCRs for countries in 21 subject areas. We find that the US dominates in all subject areas (US share ~ 40-90%). Based on the number of highly cited researchers in a country, an index of citation excellence is proposed. We find that rank order of countries based on this index is in conformity with our general understanding of research excellence, whereas the more frequently used indicator, citations per paper, gave an unacceptable rank order due to an inherent bias toward very small countries. Additionally, a high value of the index of citation excellence was found to be associated with higher concentration of highly cited researchers in affiliating organizations.     

Citation behavior in popular scientific papers: what is behind obscure citations? The case of ethnobotany

Citation studies have become an important tool for understanding scientific communication processes, as they enable the identification of several characteristics of information-retrieval behavior. This study seeks to analyze citation behavior using two popular ethnobotany articles, and our analysis is guided by the following question: when an author references a work, is he pointing out the work??s theoretical contribution, or is bias a factor in citing this reference? Citation analysis reveals an interesting phenomenon, as the majority of citing texts do not consider the theoretical contributions made by the articles cited. Two possible conclusions can be drawn from this scenario: (1) citing authors read the original texts that they cite only superficially, and (2) the works cited are not read by the vast majority of people who reference them. Thus, it is clear that even with sufficient access to reference texts; ethnobotanical studies highlight elements less relevant to the research and reproduce discussions in a non-reflective manner.     

Citation status of Turkish physics publications in foreign journals: A global analysis

We have studied the citation rates and characteristics of 572 Turkish physics publications that appeared in the source journals listed in theScience Citation Index (SCI) for the period 1982–1990 to drive the following results: The papers appeared in a set of 94 journals, and 68% of the total output went to 21 of these; half of which are journals of high impact. On the average, papers from Turkey that appeared in the American and European journals are cited at rates higher than the corresponding average papers. There has been a substantial shift of Turkish papers from European journals to American journals over the last few years. These changes are an example of the process by which science in a less developed country becomes integrated into the word scientific community.     

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.     

A comparison of citation classics in three fields of science

A sample of Citation Classics in three scientific fields was studied to uncover citing motivations. The classics were classified into basic research, methods and reviews. Number of citations received per classic, number of authors, and age of classic per category and scientific field were the parameters studied. Journals and countries accounting for the highest incidence of classics were examined. A striking parallelism was found in the parameters applied to the categories in the scientific fields studied. This parallelism suggests similar citing habits of scientists in the fields studied which should be reflected in the structures of science obtained through citation grounded bibliometric models.     

Research and citation impact of publications by the Chemistry Division at Bhabha Atomic Research Centre

The paper analyses the citations to 1733 publications published during 1970–1999 by the Chemistry Division at Bhabha Atomic Research Centre, using Science Citation Index 1982–2003 as the source data. The extent of citations received, in terms of the number of citations per paper, yearwise break up of citations, domainwise citations, self-citations and citations by others, diachronous self-citation rate, citing authors, citing institutions, highly cited papers, the categories of citing documents, citing journals and distribution of citations among them etc. are determined. During 1982–2003 chemistry Division publications have received a total of 11041 citations. The average number of citations per year was 501.86. The average number of citations per publication was 6.37. The highest number of citations received were 877 in 2001. The citation rate was peaked during 1990–2003 as maximum 9145 (82.82%) citations were received during the period. Total self-citations were 3716 (33.66%) and citations by others were 7325 (66.34%). Mean diachronous self-citation rate was 36.16. Citation time lag was zero for 144 (15.52%) papers and one year for 350 (37.72%) papers. Single authored publications (168) have received 456 (4.13%) citations and 1565 multi-authored publications have received 10585 (95.87%) citations. The core citing authors were: J. P. Mittal (695) followed by V. K. Jain (524), H. Mohan (471), T. Mukherjee (307), R. M Iyer (253), H. Pal (251), J. V. Yakhmi (211), A. V. Sapre (174), D. K. Palit (161), N. M. Gupta (128), and S. K. Kulshrestha (116). Citation life cycles of four highly cited papers was discussed. The core journals citing Chemistry Division publications were: J. Phys. Chem.-A (436 citations), Chem. Phys. Lett. (372), J. Phys. Chem. (355), J. Chem. Phys. (353), J. Organomet. Chem. (285), J. Phys. Chem.-B (279), J. Photochem. Photobiol.-A (263), Langmuir (245), J. Am. Chem. Soc. (226), Physica-C (225), Radiat. Phys. Chem. (217), Inorg. Chem. (215) and Indian J. Chem.-A (207).     

The highly cited papers of professors as an indicator of a research group's scientific performance

In the first part of the paper the citations in 1986 and 1987 of 3938 papers published in 1985 by 324 research groups in the faculties of science and of medicine of eight universities in the Netherlands are analyzed. Because of the large statistical spread of (1) the number of short-term citations of papers cited equally frequently over a long period, and (2) the number of citations over a long period of papers by the same author, short-term citation scores appear to be an unreliable indicator of a research group's contribution to science. In the second part of the paper an alternative approach is presented, based on a subdivision of the 3938 papers in papers authored by professors with 0–2, 3–8, or 9 highly cited papers (HCPs, 25 citations) to their name. Very large citation score differences were found for the three categories. For example: for papers first-authored by a professor, the average number of citations per person in 1986 and 1987 for 1985 papers was for 161 professors with 9 HCPs a factor 14 larger than for 575 professors with only 0–2 HCPs; for papers co-authored by professors, this factor was 6.6. These findings justify the conclusion that the number of HCPs scored by the professors (and other senior scientists) during their entire career is a much more reliable predictor of the performance of a research group than the number of short-term citations of the articles published by the group within a short period. A research group's contribution to science is primarily determined by the individual scientifictalents of its members.     

Identification of referencing and citation processes of scientific journals based on the citation distribution model

In this article, we firstly analyze the referencing process and the citation process of a scientific journal in theory, and find that the observed referencing or citation process includes the diffusing process and the aging process of cited literature and the publishing process of citing literature, thereby it is illuminated why the identified average publication delay ( [`(T)] = T_s + t ) \left( {\bar{T} = T_{s} + \tau } \right) was longer than the observed value. Secondly, we compare the transfer function model of the observed citing process with other classical citation distribution models and find that the model is superior to others. Finally, using the model, we identify parameters of actual referencing and citation processes from data of age distributions of references and citations of 38 journals of neurology and applied mathematics in JCR, respectively; and then compare differences of identified parameters and obtain some interesting conclusions.     

A re-examination of the Ortega hypothesis: The Dutch case

Using data collected for a sample of 69 Dutch physicists, the present study employs a multivariate approach in order to re-examine the Ortega hypothesis. Stated succinctly, the Ortega hypothesis maintains that, in large measure, science has progressed through the efforts of many quite average scientists. Based on a combined citation search of 2763 source and reference authors, eminent scientists are shown to cite other eminent scientists, although not to the extent reported among American physicists in earlier research by theColes. The tendency for eminent scientists to cite other eminent scientists is a rather recent occurrence in The Netherlands, and may signal a major trend in the differential allocation of facilities and resources which, in turn, impact on the development of science in that country. In addition to the citation rate of source author's year of article's publication and length of source author's professional experience, are also shown to be significantly related to the eminence of reference authors cited, thereby signaling caution concerning rejection of the Ortega hypothesis.     

Citations and scientific progress: Comparing bibliometric measures with scientist judgments

This project compares various bibliometric measures and scientists' own judgments. Publication and cittion data are compiled for two cohorts of chemists awarded Sloan Fellowships. Citation patterns differ substantially between most cited papers and those these authors identify as their best. Theoretical, empirical, and methodological papers are contrasted as well. In addition, temporal citation patterns show that recognition spreads beyond the research area of a particular paper to yield cross-disciplinary citation surprisingly rapidly. Results suggest the utility of studying citation patterns among the Institute for Scientific Information Subject Categories, but also caution against equating publication and citation counts with scientific progress.