Thomson ISI, the company whose Web of Science tool dominates academic literature searches online, has announced that open-access journals are having an increasing impact in the world of scientific research.

Just 191 of the 8,700 journals indexed by the Web of Science search engine use the open-access publishing model. But that number is constantly increasing as new open-access journals are being founded and existing journals are changing their access model. Some argue that the fact that they are listed by Web of Science at all is a testament to the development of the open-access movement.

In a paper entitled The Impact of Open Access Journals, Thomson ISI reports that there is no discernable difference in terms of citation impact or frequency of citation between open-access and other journals.

However, these findings apply only to those open-access journals that ISI has already accepted for inclusion in Web of Science. ISI has rigorous selection criteria to ensure that only top quality content is indexed. It reviews nearly 2,000 journals each year, but accepts only 10-12 per cent.

Link to ISI paper on open-access journals