Wednesday, September 23, 2015

Tools to visualize connections between academic publications

Academic researchers publish a lot of papers. One estimate puts the count at 1.8 million articles published each year, in about 28,000 journals (in 2012). The challenge is to make sense of all these publications.

With the raise of visualization tools, one would expect that there are some great tools out there that provide researchers with easy to use visualizations of how papers and authors are connected.

I distinguish between three different types of visualization tools: Impact factor, co-authors, and citations. Unfortunately, there currently seems to be no tool available that combines all three.

1. Tools to visualize the impact factor of a journal (impact factor diagrams)
Eigenfactor [free] offers dynamic graphs of the impact factor of journal by field. One can choose the field of interest, e.g. chemistry, education, or physics. The dynamic graph shows the journals with the highest impact factors on a timeline from 1997 to the present (slider below the graph). Eigenfactor is an academic research project co-founded by Jevin West and Carl Bergstrom and sponsored by the Bergstrom Lab in the Department of Biology at the University of Washington.
Eigenfactor 'motion graphs' show the impact factor of journals (on a timeline)
2. Tools to visualize the relations between co-authors (co-author mapping)
Do you want to see which researchers published together as co-authors? The 'Visual Explorer' of Microsoft Academic Search [free] focuses on the relations between people. After selecting a certain author, one can choose 'co-author path' in the left hand menu. The dynamically generated diagram show the co-authors of this researcher ('co-author graph'), how this researcher is connected to another researcher ('co-author path' - similar to the Six degrees of Kevin Bacon index), and who cited this researcher ('citation graph').
The 'Visual Explorer' by Microsoft Academic search shows relations between co-authors
3. Tools that visualize the citations between papers (citation mapping)
Do you want to know which papers cited a certain publication (forward mapping)? Do you want to see which papers were cited by a publication? Papercube [free] provides a visual navigation of academic citation networks. The data is a static snapshot of the CiteSeer digital library from 2004. The tools only serves to demonstrate the features but is unfortunately no longer updated.
Papercube shows academic citation networks (based on 2004 data)
Another tool to visualize citation networks is the Web of Science citation graph [paid through libraries]. This tool generates a dynamic graph of citations (forward and backwards). One can click on a specific publication to see details and to re-center the diagram.
Web of Science citation graph
The VOSviewer (which stands for 'visualizing scientific landscapes) is a free stand-alone tool developed by Leiden University. The VOSviewer tool can be used for constructing and visualizing bibliometric networks. These networks may for instance include journals, researchers, or individual publications, and they can be constructed based on co-citation, bibliographic coupling, or co-authorship relations. Reference lists can be imported from Web of Science, Scopus, and PubMed.

SciMAT (developed by the University of Granada, Spain) is an open source (GPLv3) software tool developed to perform a science mapping analysis under a longitudinal framework. SciMAT allows  to conduct co-word, author co-citation, journal co-citation, author co-citation, bibliographic coupling, journal bibliographic coupling and author bibliographic coupling.
A list of other software for mapping scientific publications:

Given the advances in data analytics, it is surprising (and disappointing) that there are no better designed tools for academics to explore and discover connections between publications.