Betweenness and diversity in journal citation networks as measures of interdisciplinarity—A tribute to Eugene Garfield

Authors : Loet Leydesdorff, Caroline S. Wagner, Lutz Bornmann

Journals were central to Eugene Garfield’s research interests. Among other things, journals are considered as units of analysis for bibliographic databases such as the Web of Science and Scopus. In addition to providing a basis for disciplinary classifications of journals, journal citation patterns span networks across boundaries to variable extents.

Using betweenness centrality (BC) and diversity, we elaborate on the question of how to distinguish and rank journals in terms of interdisciplinarity. Interdisciplinarity, however, is difficult to operationalize in the absence of an operational definition of disciplines; the diversity of a unit of analysis is sample-dependent. BC can be considered as a measure of multi-disciplinarity.

Diversity of co-citation in a citing document has been considered as an indicator of knowledge integration, but an author can also generate trans-disciplinary—that is, non-disciplined—variation by citing sources from other disciplines.

Diversity in the bibliographic coupling among citing documents can analogously be considered as diffusion  or differentiation of knowledge across disciplines. Because the citation networks in the cited direction reflect both structure and variation, diversity in this direction is perhaps the best available measure of interdisciplinarity at the journal level.

Furthermore, diversity is based on a summation and can therefore be decomposed; differences among (sub)sets can be tested for statistical significance. In the appendix, a general-purpose routine for measuring diversity in networks is provided.

URL : Betweenness and diversity in journal citation networks as measures of interdisciplinarity—A tribute to Eugene Garfield




Prevalence and citation advantage of gold open access in the subject areas of the Scopus database

Authors : Pablo Dorta-González, Yolanda Santana-Jiménez

The potential benefit of open access (OA) in relation to citation impact has been discussed in the literature in depth. The methodology used to test the OA citation advantage includes comparing OA vs. non-OA journal impact factors and citations of OA versus non-OA articles published in the same non-OA journals.

However, one problem with many studies is that they are small -restricted to a discipline or set of journals-. Moreover, conclusions are not entirely consistent among research areas and ‘early view’ and ‘selection bias’ have been suggested as possible explications. In the present paper, an analysis of gold OA from across all areas of research -the 27 subject areas of the Scopus database- is realized.

As a novel contribution, this paper takes a journal-level approach to assessing the OA citation advantage, whereas many others take a paper-level approach. Data were obtained from Scimago Lab, sorted using Scopus database, and tagged as OA/non-OA using the DOAJ list.

Jointly with the OA citation advantage, the OA prevalence as well as the differences between access types (OA vs. non-OA) in production and referencing are tested. A total of 3,737 OA journals (16.8%) and 18,485 non-OA journals (83.2%) published in 2015 are considered. As the main conclusion, there is no generalizable gold OA citation advantage at journal level.


Opening Up Communication: Assessing Open Access Practices in the Communication Studies Discipline

Author : Teresa Auch Schultz


Open access (OA) citation effect studies have looked at a number of disciplines but not yet the field of communication studies. This study researched how communication studies fare with the open access citation effect, as well as whether researchers follow their journal deposit policies.


The study tracked 920 articles published in 2011 and 2012 from 10 journals and then searched for citations and an OA version using the program Publish or Perish. Deposit policies of each of the journals were gathered from SHERPA/RoMEO and used to evaluate OA versions.


From the sample, 42 percent had OA versions available. Of those OA articles, 363 appeared to violate publisher deposit policies by depositing the version of record, but the study failed to identify post-print versions for 87 percent of the total sample for the journals that allowed it.

All articles with an OA version had a median of 17 citations, compared to only nine citations for non-OA articles.

Discussion & Conclusion

The citation averages, which are statistically significant, show a positive correlation between OA and the number of citations.

The study also shows communication studies researchers are taking part in open access but perhaps without the full understanding of their publisher’s policies.

URL : Opening Up Communication: Assessing Open Access Practices in the Communication Studies Discipline


Understanding the Impact of Early Citers on Long-Term Scientific Impact

Authors : Mayank Singh, Ajay Jaiswal, Priya Shree, Arindam Pal, Animesh Mukherjee, Pawan Goyal

This paper explores an interesting new dimension to the challenging problem of predicting long-term scientific impact (LTSI) usually measured by the number of citations accumulated by a paper in the long-term.

It is well known that early citations (within 1-2 years after publication) acquired by a paper positively affects its LTSI. However, there is no work that investigates if the set of authors who bring in these early citations to a paper also affect its LTSI.

In this paper, we demonstrate for the first time, the impact of these authors whom we call early citers (EC) on the LTSI of a paper. Note that this study of the complex dynamics of EC introduces a brand new paradigm in citation behavior analysis.

Using a massive computer science bibliographic dataset we identify two distinct categories of EC – we call those authors who have high overall publication/citation count in the dataset as influential and the rest of the authors as non-influential.

We investigate three characteristic properties of EC and present an extensive analysis of how each category correlates with LTSI in terms of these properties. In contrast to popular perception, we find that influential EC negatively affects LTSI possibly owing to attention stealing.

To motivate this, we present several representative examples from the dataset. A closer inspection of the collaboration network reveals that this stealing effect is more profound if an EC is nearer to the authors of the paper being investigated.

As an intuitive use case, we show that incorporating EC properties in the state-of-the-art supervised citation prediction models leads to high performance margins.

At the closing, we present an online portal to visualize EC statistics along with the prediction results for a given query paper.


A Century of Science: Globalization of Scientific Collaborations, Citations, and Innovations

Authors : Yuxiao Dong, Hao Ma, Zhihong Shen, Kuansan Wang

Progress in science has advanced the development of human society across history, with dramatic revolutions shaped by information theory, genetic cloning, and artificial intelligence, among the many scientific achievements produced in the 20th century. However, the way that science advances itself is much less well-understood.

In this work, we study the evolution of scientific development over the past century by presenting an anatomy of 89 million digitalized papers published between 1900 and 2015.

We find that science has benefited from the shift from individual work to collaborative effort, with over 90% of the world-leading innovations generated by collaborations in this century, nearly four times higher than they were in the 1900s.

We discover that rather than the frequent myopic- and self-referencing that was common in the early 20th century, modern scientists instead tend to look for literature further back and farther around.

Finally, we also observe the globalization of scientific development from 1900 to 2015, including 25-fold and 7-fold increases in international collaborations and citations, respectively, as well as a dramatic decline in the dominant accumulation of citations by the US, the UK, and Germany, from 95% to 50% over the same period.

Our discoveries are meant to serve as a starter for exploring the visionary ways in which science has developed throughout the past century, generating insight into and an impact upon the current scientific innovations and funding policies.


The scientific impact of nations on scientific and technological development

Authors : Aurelio Patelli, Giulio Cimini, Emanuele Pugliese, Andrea Gabrielli

Determining how scientific achievements influence the subsequent process of knowledge creation is a fundamental step in order to build a unified ecosystem for studying the dynamics of innovation and competitiveness.

Yet, relying separately on data about scientific production on one side, through bibliometric indicators, and about technological advancements on the other side, through patents statistics, gives only a limited insight on the key interplay between science and technology which, as a matter of fact, move forward together within the innovation space.

In this paper, using citation data of both scientific papers and patents, we quantify the direct impact of the scientific outputs of nations on further advancements in science and on the introduction of new technologies.

Our analysis highlights the presence of geo-cultural clusters of nations with similar innovation system features, and unveils the heterogeneous coupled dynamics of scientific and technological success.

This study represents a first step in the buildup of a comprehensive framework for knowledge creation and innovation.


Reconsidering the gold open access citation advantage postulate in a multidisciplinary context: an analysis of the subject categories in the Web of Science database 2009-2014

Authors : Pablo Dorta-González,  Sara M. González-Betancor, María Isabel Dorta-González

Since Lawrence in 2001 proposed the open access (OA) citation advantage, the potential benefit of OA in relation to the citation impact has been discussed in depth.

The methodology to test this postulate ranges from comparing the impact factors of OA journals versus traditional ones, to comparing citations of OA versus non-OA articles published in the same non-OA journals.

However, conclusions are not entirely consistent among fields, and two possible explications have been suggested in those fields where a citation advantage has been observed for OA: the early view and the selection bias postulates.

In this study, a longitudinal and multidisciplinary analysis of the gold OA citation advantage is developed. All research articles in all journals for all subject categories in the multidisciplinary database Web of Science are considered.

A total of 1,137,634 articles – 86,712 OA articles (7.6%) and 1,050,922 non-OA articles (92.4%)- published in 2009 are analysed. The citation window considered goes from 2009 to 2014, and data are aggregated for the 249 disciplines (subject categories).

At journal level, we also study the evolution of journal impact factors for OA and non-OA journals in those disciplines whose OA prevalence is higher (top 36 subject categories). As the main conclusion, there is no generalizable gold OA citation advantage, neither at article nor at journal level.