Summary: The Research Impact of Open Access Journals, Summary of a Presentation by Kristin Antelman, North Carolina State University Libraries

The purpose of this study was to examine whether articles have a greater impact in citation numbers if they are open access compared to non-open access in the same journals.

Antelman sampled articles from ten leading journals in philosophy, political science, electrical and electronic engineering, and mathematics as shown by the Institute for Scientific Information’s (ISI) journal citation reports for 2002.

Antelman chose fifty open access and fifty restricted articles in each discipline covering 2001 - 2002 (philosophy was sampled from 1999-2000 because of the lower citation rates in this discipline).  She searched the article titles in Google and recorded the number of citations for each article.  Some were found in open access and easily clickable. Others appeared in the Google results screen but when the link was clicked, the user was asked for a password or a fee (indicating that it was not open access).  Some of the articles were available in open access at the author's home page, disciplinary repositories, pre-print or reprint repositories. Antelman compared the means for each discipline and tested for significance.

Antelman pointed to three citation advantage factors that motivate users to cite some articles over others.

1. QB- Quality Bias - Is the article of sufficient quality to cite in a papers?

2. BA - Early advantage - Is the article posted early before publication in a journal?

3. OA - Open access advantage – Is the article easily accessible on the web?

 Antelman indicated that open access journals have greater citation impact than those that are not open access.  If users click the open access link at a library computer or at a home computer, they are likely to read and cite those articles.  These articles meet the users' needs and are considered "good enough." to cite. 

When Antelman compared some of her results to the citation frequencies in ISI, the comparison showed that the most heavily cited journals were not always open access journals. The heavy citation rate may be due to the fact that members of a discipline will tend to cite important articles by a colleague.  This would inflate the citation impact. Although journal level impact factors are routinely used to evaluate the prestige of a journal, these factors correlate poorly with citations of individual articles. But if the journal is not freely available in an open access mode, many students and researchers will ignore the article and cite those that they can find freely on the internet.

Some copyright agreements allow authors to post the articles on their pages after publication in the journal. Some articles are posted on preprint pages prior to publication or reprint pages after publication. Antelman concluded that open access articles have a greater research impact than articles that are not freely available. Scholars are becoming more cognizant of the advantages of publishing in open access settings.  This has implications for libraries that are trying to meet these needs by providing a wider range of open access initiatives for their users.