  The number of papers published in journals indexed by the Web of Science core
collection is steadily increasing. In recent years, nearly two million new
papers were published each year; somewhat more than one million papers when
primary research papers are considered only (articles and reviews are the
document types where primary research is usually reported or reviewed).
However, who reads these papers? More precisely, which groups of researchers
from which (self-assigned) scientific disciplines and countries are reading
these papers? Is it possible to visualize readership patterns for certain
countries, scientific disciplines, or academic status groups? One popular
method to answer these questions is a network analysis. In this study, we
analyze Mendeley readership data of a set of 1,133,224 articles and 64,960
reviews with publication year 2012 to generate three different kinds of
networks: (1) The network based on disciplinary affiliations of Mendeley
readers contains four groups: (i) biology, (ii) social science and humanities
(including relevant computer science), (iii) bio-medical sciences, and (iv)
natural science and engineering. In all four groups, the category with the
addition "miscellaneous" prevails. (2) The network of co-readers in terms of
professional status shows that a common interest in papers is mainly shared
among PhD students, Master's students, and postdocs. (3) The country network
focusses on global readership patterns: a group of 53 nations is identified as
core to the scientific enterprise, including Russia and China as well as two
thirds of the OECD (Organisation for Economic Co-operation and Development)
countries.
