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Editorial

Non-Open Access and Its Adverse Impact on Molecules

MDPI Center, Matthaeusstrasse 11, CH-4057 Basel, Switzerland
Molecules 2007, 12(7), 1436-1437; https://doi.org/10.3390/12071436
Submission received: 10 July 2007 / Accepted: 16 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, 70 papers (just under 50% of the total) were published in the password protected (non-Open Access) area of Molecules. Not undexpectedly, this reduced number of Open Access papers had a significant influence on the impact factor of Molecules, which was reduced from 1.113 in 2005 to 0.841 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 are presented in Table 1.
Table 1. Open Access (OA) and non-Open Access (non-OA) papers published in Molecules in 2005 [3].
Table 1. Open Access (OA) and non-Open Access (non-OA) papers published in Molecules in 2005 [3].
Number of papers 1Number of citations 2Average citation
Non-OA 370430.614
OA74901.216
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.
Like Molecules, in 2005 another MDPI journal, International Journal of Molecular Sciences, also published a significant percentage of papers in its password protected (non-Open Access) area. The impact factor of International Journal of Molecular Sciences was also reduced from 1.467 in 2005 to 0.679 in 2006. The statistical data for non-OA and OA are presented in Table 2.
As shown in Table 1 and Table 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.
Table 2. Open Access (OA) and non-Open Access (non-OA) papers published in International Journal of Molecular Sciences in 2005 [3].
Table 2. Open Access (OA) and non-Open Access (non-OA) papers published in International Journal of Molecular Sciences in 2005 [3].
Number of papers 1Number of citations 2Average citation
Non-OA 31150.455
OA13191.462
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.
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, and 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].

Acknowledgments

I am grateful for comments and corrections made by Dr. Ricardo Aparicio and Dr. Derek McPhee.

References and Notes

  1. Lin, S.-K. Open Access and Author’s Open Choice. Molecules 2005, 10, 583–584. [Google Scholar] (PDF format 16 K at http://www.mdpi.org/molecules/papers/10060583.pdf; HTML format at http://www.mdpi.org/molecules/html/10060583.htm)
  2. Lin, S.-K. Delayed Open Access or Permanent Non-Open Access. Molecules 2006, 11, 496–497. [Google Scholar] (PDF format 15 K at http://www.mdpi.org/molecules/papers/11070496.pdf; HTML format at http://www.mdpi.org/molecules/html/11070496.htm)
  3. The raw data in Excel format is available upon request.
  4. For more information, visit the www.mdpi.org/oaj-supports.htm website.

Share and Cite

MDPI and ACS Style

Lin, S.-K. Non-Open Access and Its Adverse Impact on Molecules. Molecules 2007, 12, 1436-1437. https://doi.org/10.3390/12071436

AMA Style

Lin S-K. Non-Open Access and Its Adverse Impact on Molecules. Molecules. 2007; 12(7):1436-1437. https://doi.org/10.3390/12071436

Chicago/Turabian Style

Lin, Shu-Kun. 2007. "Non-Open Access and Its Adverse Impact on Molecules" Molecules 12, no. 7: 1436-1437. https://doi.org/10.3390/12071436

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