First Significant Broad Study Conducted on Median Half-Life and Variations in Usage by Discipline
The following independent study analyzes the usage pattern of articles published in over 2800 academic and professional journals. It identifies the “half-life” of journals — the amount of time it takes for articles in a journal to receive half of their lifetime total downloads — and is the first major broad-based report conducted on this topic.
Phil Davis, Ph.D., an independent researcher and former science librarian, analyzed lifetime usage data from 2812 journals representing the works of 13 scholarly publishers in 10 distinct scholarly disciplines including life sciences, engineering, social sciences and the humanities.
• Journal article usage varies widely within and across disciplines
• It takes significant time for journals to experience half of the lifetime downloads (“half-life”) of their articles
• Articles in the majority of journals receive more than half of their lifetime downloads three or more years after publication
• Only 3% of journals in all fields have half-lives of 12 months or less
• Health sciences articles have the shortest median half-life of the journals analyzed, but still more than 50% of health science journals have usage half-lives longer than 24 months
• In fields with the longest usage half-lives, including mathematics and the humanities, more than 50% of the journals have usage half-lives longer than 48 months
“There has been extensive dialogue surrounding public access and embargo periods but assumptions, opinions and ideas have never been grounded in actual data about usage of journal literature. The White House Office of Science and Technology Policy has called for evidence-based procedures to set appropriate embargo periods for public access to articles reporting on federally funding research. Rigorous, scientifically sound studies such as this are critical to setting rational and effective policy,” said John Tagler, Vice President and Executive Director, Professional and Scholarly Publishing, Association of American Publishers.
“Publishers have consistently expressed the view that a one-size-fits-all embargo period for scholarly works will not fairly address disparities in journal usage and, in turn, damage the sustainability of high-quality, peer-reviewed science communication,” he added. “This study provides comprehensive data to support those views and, in some cases, demonstrates that half-lives are even longer than generally assumed.”
In response to the February 2013 OSTP directive, federal agencies are developing plans to support increased public access to research funded by the government. AAP publishers support the OSTP directive and have engaged with agencies and other stakeholders regarding public access. While the study was funded by the PSP Division of AAP in response to interest from federal agencies and others in relevant data, participating publishers submitted the data to Davis individually and the Association had no involvement in Davis’s analysis.