Revisiting Methodology for Identifying Open Access Advantages | SpringerLink

Abstract:  Although many empirical studies have investigated whether open access increases citations, researchers have not reached a consensus regarding the issue. This study revisited the methodology for identifying the effects of open access and revealed the causes for contradictory conclusions using four indices for journals that transitioned from subscription to open access. The four indices are two citation scores along with the number of citations and number of articles for eight journals independently launched by leading publishers. Correlation coefficients were used to compare the time trends in the values of the four indices. Although the aggregated data of the eight journals indicated that open access had a positive effect, the effect varied across journals. A few journals produced different results between the two citation scores as well as between citation scores and number of citations or articles. Furthermore, a publisher’s choice of which journal to shift to open access influenced their performance after the shift. Therefore, results varied based on the choice of journals, indices, and types of data (aggregated vs. individual journals), leading to contradictory conclusions regarding open access advantages.