Article 50 Million: An Estimate of the Number of Scholarly Articles in Existence Arif E. Jinha
Faculty of Post-Doctoral and Graduate Studies
University of Ottawa
How many scholarly research articles are there in existence? Journal articles first appeared in 1665,and the cumulative total is estimated here to pass 50 million in 2009. This sum was arrived at based on published figures for global annual output for 2006, and analyses of annual output and growth rates published in the last decade.
From the first model of the modern journal, Le Journal des Sçavans, published in France in 1665, followed by Philosophical Transactions published by the Royal Society in London later that year, the number of active scholarly journal titles has increased steadily. In 2006 there were roughly 23750 titles. There are direct correlations between the numbers of researchers, journals and articles. Björk et al. argue that changes in the dynamics of literature-based research, provoked by the communications revolution, have made the article itself relevant today as the basic molecular unit of research communication.
The correlations are revealed by studies in the past decade on global research output that have reported the growth rate and annual figures for researchers, journals and articles . Researchers retire, but more new researchers emerge. Journals fold, but a higher number are introduced for the first time. Changes over time in the number of active researchers and journals describe the dynamics of both publishing and research, and the increase in absolute size of active production However, the article has a static nature that makes it unique as a metric. Articles, once created and published, are rarely destroyed. They can always be re-activated and through citation each article occupies a position in the architecture that researchers can continue to build upon. The article is born essentially through the efforts of journals and their publishers, but articles survive the death of journal titles. Though disciplines develop distinct fields of inquiry, there are ultimately no fixed boundaries in scholarship – this is a single system of documented written knowledge.
Therefore a metric that describes the quantitative whole of this system – the global total of all modern scholarly journal articles in existence at the present moment or at any point in time – can be useful as a starting point for research into the structure of the system itself. Further, getting better estimates of the global volume of research can enable information scientists to achieve a great deal. The estimates allow them to map the geography of knowledge production, identify routes to retrieval of articles, extract 2
content, while ensuring its preservation and its availability for use. This paper presents an estimate for the total number of all peer-reviewed articles published worldwide since 1665. Included is a replication of earlier studies showing the current numbers of active journal titles, reported here for the year 2009. Literature Review
Inquiry into the scope of production of scholarly articles through peer-reviewed journals and the universe of journal titles and articles has never been precise. However, several works exist that attempt to quantify global output of scholarship dating to the post-War ‘Big Science’ period as well as more recent works from the 1990s until present.
In 1963, Derek de Solla Price plotted the growth of journal titles from 1665 to 2000 giving rise to predictions of an astronomical 1 million journal titles by year 2000. Price also identified key relationships between research investment, the numbers of researchers, and the numbers of journal titles, abstracts and articles. These relationships have been carried forward in more recent research. Estimates of the numbers of journal titles worldwide were made by King et al in 1977 at 57,400 and in 1995 by Meadows and...