Molecular Sciences
© 2007 by MDPI
http://www.mdpi.org/ijms
Editorial
Shu-Kun Lin
Molecular Diversity Preservation International (MDPI), Matthaeusstrasse 11, Basel CH-4057, Switzerland; Tel. +41 79 322 3379, Fax: +41 61 302 8918, E-mail: [email protected], http://www.mdpi.org/lin
Received: 10 July 2007 / Published: 16 July 2007
In 2005 and 2006 papers were published in MDPI journals in both non-Open Access (non-OA) and Open Access (OA) form [1,2]. In 2005, 11 papers (just under 50% of the total) were published in the password protected (non-Open Access) area of International Journal of Molecular Sciences. Not unexpectedly, this reduced number of Open Access papers had a significant influence on the impact factor of International Journal of Molecular Sciences, which was reduced from 1.467 in 2005 to 0.679 in 2006. According to the methods used in calculating impact factors, the number of papers published in 2005 and the number of citations were used in the calculation of the 2006 impact factor. The statistical data for non-OA and OA papers are presented in Table 1.
Table 1. Open Access (OA) and non-Open Access (non-OA) papers published in International Journal of Molecular Sciences in 2005 [3].
|
|
Number of papers 1 | Number of citations 2 | Average citation |
|---|---|---|---|
| Non-OA3 | 11 | 5 | 0.455 |
| OA | 13 | 19 | 1.462 |
1 Only research papers and review papers are counted. Other materials such as editorials, are not included. 2 Up to 13 July 2007, according to Web of Sciences. 3 By April 2007, all the non-OA papers were changed to Open Access.
Similar to the International Journal of Molecular Sciences, in 2005 another MDPI journal, Molecules, also published a significant percentage of papers in its password protected (non-Open Access) area. The impact factor of this journal was also reduced from 1.113 in 2005 to 0.841 in 2006. The statistical data for non-OA and OA papers are presented in Table 2.
Int. J. Mol. Sci. 2007, 8
Table 2. Open Access (OA) and non-Open Access (non-OA) papers published in Molecules in 2005 [3].
|
|
Number of papers 1 | Number of citations 2 | Average citation |
|---|---|---|---|
| Non-OA 3 | 70 | 43 | 0.614 |
| OA | 74 | 90 | 1.216 |
1 Only research papers and review papers are counted. Other materials such as editorials, are not included. 2 Up to 13 July 2007, according to Web of Sciences. 3 By April 2007, all the non-OA papers were changed to Open Access.
As shown in Tables 1 and 2, the non-Open Access papers and their obviously lower citation numbers appear to be the main reason behind the reduced impact factors of these two journals, where almost half of the papers published were in non-OA form.
As a contrast, the MDPI journal Sensors (http://www.mdpi.org/sensors/) published only a very small number of non-Open Access papers in 2005, and its impact factor increased slightly from 1.208 in 2005 to 1.373 in 2006.
Since April 2007, we have granted full Open Access to all the papers published in all MDPI journals in 2005 and 2006. In 2007, we have published papers exclusively in Open Access form. We expect this will be reflected in an increase in impact factors come the next evaluation.
As always, we welcome our reader’s opinions on these matters [4]. Messages with a suitable Subject header should be sent to [email protected] or [email protected].
I am grateful for comments and corrections made by Dr. Ricardo Aparicio and Dr. Derek McPhee.
© 2007 by Molecular Diversity Preservation International (MDPI).