Scientific impact of open access journals: A research on citation indexes

The aim of this research was to assess the scientific impact of open access journals (OAJs). For this purpose, the descriptive method was used and research data were collected on Directory of Open Access Journal (DOAJ), Journal Citation Reports (JCR) and websites of open access journals, and statistically analyzed. According to data between JCR 2000 and 2015, the number of OAJs increased from 249 (4%) to 1,320 (12%) in 16 years. In this period, while the share of OAJs published by commercial publishers and universities increased from 23% to 42% and 20% to 22%, and civil society organizations (CSOs) and other types of publishers decreased from 36% to 26% and from 20% to 10%, respectively. Commercial publishers, CSOs, universities and other publishers charged article processing fees for OAJs by 79%, 46%, 31% and 17%, respectively. There was a significant relationship between open access publisher types and whether or not to charge article processing fees. Furthermore, there was a positive correlation between the article processing fee and the metrics, albeit varied by disciplines and metrics, and the metrics of OAJs that charged article processing fees were higher than those who did not. The metrics of OAJs increased significantly after 5, 10 and 15 years. Metrics of toll access journals were higher than OAJs, again, albeit varied by disciplines and metrics. It may be useful to increase the number of OAJs and to prioritize the value of individual researches rather than journal-level metrics in research assessment systems.