Open Access News

News from the open access movement

Saturday, September 08, 2007

Where to expect an OA advantage and where not to

Stevan Harnad, Where There's No Access Problem There's No Open Access Advantage, Open Access Archivangelism, September 7, 2007. 

SummaryKurtz & Henneken (2007) report that the citation advantage of astrophysics papers self-archived as preprints in Arxiv is caused by (1) Early Advantage (EA) (earlier citations for papers self-archived earlier) and (2) Quality Bias (QB) (a self-selection bias toward self-archiving higher quality papers) and not by (3) Open Access (OA) itself (being freely accessible online to those who cannot afford subscription-toll access). 

K & H suggest: "[T]here is no 'Open Access Advantage' for papers from the Astrophysical Journal because in a well funded field like astrophysics essentially everyone who is in a position to write research articles has full access to the literature." 

This seems like a perfectly reasonable explanation for K&H's findings. Where there is no access problem, OA cannot be the cause of whatever higher citation count is observed for self-archived articles. 

We (Hajjem & Harnad 2007) have conducted a similar study, but across the full spectrum of disciplines, measuring the citation advantage for mandated and unmandated self-archiving for articles from four Institutional Repositories that have self-archiving mandates, each compared to articles in the very same journal and year by authors from other institutions (on the assumption that mandated self-archiving should have less of a self-selection Quality Bias than unmandated self-archiving). 

We again confirmed the citation advantage for self-archiving, and found no difference in the size of that advantage for mandated and unmandated self-archiving. It is likely that the size of the access problem differs from field to field, and with it the size of the OA citation advantage. It is unlikely that most fields are as well-heeled as astrophysics.