The Impact Factor of Open Access journals

In the world of Open Access publishing the golden road has received a great deal of attention. At least this is what our researchers seem to remember. Of course there are other roads to open access, but I want to present the impact factors of the journals facilitating the golden road to open access. This blogpost lists all open access journals included in DOAJ and assigned an Journal Impact Factor in the JCR 2009. The reason for this, is that our researchers see publishing in open access journals as the simplest way of achieving open access to their work, but on the other hand they are required for judgement of the citation impact that they publish in journals covered by Web of Science and therefore the Journal Citation Reports (JCR).

In the past there have been studies on citation impact of the open access journals that have actually received a journal impact factor from Thomson Reuters Scientific (formerly ISI). The first was by (McVeigh 2004) followed by (Vanouplines and Beullens 2008) (in Dutch, and not openly accessible) and recently by (Giglia 2010). These consecutive studies showed an increasing number of open access journals that received an Journal Impact Factor from Thomson Reuters. McVeigh reported 239 OA journals for the JCR 2004, Vanouplines reported 295 OA journals for the JCR 2005 and Giglia reported 385 OA journals for the JCR 2008 (there are some methodological issues that make these figures not entirely comparable).

The pitfall of these studies is that although they showed interesting figures and additional analyses, none of these studies actually published the list of open access journals that received an impact factor. The sole purpose of this blogpost is to publish this actual list. The probable reason for the previous authors is that the impact factors are proprietary information from Thomson Reuters. You are not allowed to publish these figures. On the other hand most publishers, use it in all their marketing outings for their journals. So the journal impact factor is virtually information in the public domain.

To avoid any intellectual property problems with Thomson Reuters I have included the ScimagoJR and Scopus SNIP indicator for the journals rather than the Journal Impact Factor. The correlation for this set of journals between SNIP and IF was 0.94 and between SJR and IF was 0.96. In total 619 journals from DOAJ were present in the JCR 2009 report (Science and Social Science & Humanities version deduplicated). The growth in journal coverage is due to the growth in OA journals and the significant expansion of journal coverage in 2008. On the other hand looking at the journal list of Scopus indexed journals I note that they include some 1365 journals open access journal which have a ScimagoJR or SNIP.

For the current table I matched the journal list from DOAJ downloaded on December 13th 2010, with the deduplicated list of the JCR 2009 indexed journals. This journal set of 619 journals was matched against the journal list from journalmetrics.com to include the ScimagoJR 2009 and SNIP2009 as well. For each journal the subject categories indicated by DOAJ were included. The journals were sorted alphabetically on subjects and descending IF within a subject. For the following table journals with multiple subject assignments in DOAJ were included in their different categories as well. This expanded the list to 782 lines. Finally the column with impact factors was removed, showing only the ScimagoJR and SNIP for the journals. A few journals were not assigned a ScimagoJR or SNIP, but these were assigned a Journal Impact Factor. In some cases this was due to differences in journal coverage between Scopus and Web of Science, but in a few cases this appears also the problem of different ISSN assignments by the respective databases.

Download: List of open access journals that are assigned an Impact Factor in the JCR 2009 showing their respective SNIP and ScimagoJR for 2009.

Have fun with this list

References

Giglia, E. (2010). The Impact Factor of Open Access journals: data and trends. ELPUB 2010 International Conference on Electronic Publishing, Helsinki (Finland), 16-18 June 2010. http://dhanken.shh.fi/dspace/bitstream/10227/599/72/2giglia.pdf and http://hdl.handle.net/10760/14666.

McVeigh, M.E. (2004). Open Access Journals in the ISI Citation Databases: Analysis of Impact Factors and Citation Patterns A citation study from Thomson Scientific, Thomson Scientific. http://science.thomsonreuters.com/m/pdfs/openaccesscitations2.pdf

Vanouplines, P. & R. Beullens (2008). De impact van open access tijdschriften. IK Intelectueel Kapitaal 7(5): 14-17. (In Dutch, Not OA available)

Possibly related posts
Another expansion of journal coverage by Thomson

Impact factors and Scimago JR compared

In December I promised to look into more detail of the newly launched Scimago Country & Journal Rank database. Scimago has attracted some attention in the blogosphere outside Spain since December and got some serious attention from Declan Butler as a news item in Nature (Subscription required).

It is too early for some thorough in-depth investigations of this new database, but the better blog reactions were at Information Research and a second time again and the Biomed Central Blog . They both had an issue of self interest to see where they where their journals were standing in this new database. We have to wait a bit longer for the reviews in the scholarly literature, I’m afraid.

Meanwhile I have looked into this database a bit more closely. In this blogpost I report some of my findings. My reason to look into this database more closely is mainly triggered by the fact that it allows us –librarians- to evaluate the rankings of a larger set of journals in a quantitative way. Impact factors have played a role in the decisions on journal subscriptions and cancellations –albeit not the sole criterion- How does the SJR compare to the impact factor is my main question.

SJR is “an indicator that expresses the number of connections that a journal receives through the citation of its documents divided between the total of documents published in the year selected by the publication, weighted according to the amount of incoming and outgoing connections of the sources.” In essence is the SJR an Pagerank type of indicator in which citations from highly ranked journals increase the ranking of the journal.

To gain more understanding SJR and I have looked at the journals in the subject category ‘Library and Information Science’. This category includes some 98 journals. It is important to note that SCImago JR has a much more refined subject categorization than included in Scopus itself. Although I speculate that this subject categorization is possibly somewhere under the hood in Scopus as well. The corresponding category in JCR is Information ‘Science & Library Science’ which contains 53 journals.

It is really easy to transfer the data from Simago JR to excel, where it always take a bit more clicks (making a marked list) and using the print export to get the data into excel. Interesting to note that in the web environment SCImago uses a European number notation with comma’s indicating the fraction and the dot indicating the thousands. On transfer to excel this is corrected automatically. A minor point from SCImago is that ISSN numbers are lacking from the exported data. In JCR the full journal titles are not exported.

The journals from JCR were matched manually against the journals from SCImago since a shared field was missing. Only a few journals from JCR were not found directly in the downloaded journals from SCImago. The journals ‘Journal of the American Medicals Information Association’, ‘Information and Management’ and ‘Journal of Scholarly Publishing’ were included in other journal categories than ‘Library and Information Science’. Furthermore it was noted that the journal ‘International Journal of the Geographical Information Science’ was included twice in the list of Library and Information Science journals at rank 5 and rank 33 again. In the processing the journal at rank 33 was dropped from the list. In the JCR the Journal of Government Information is still include albeit it was from 2005 already included in Government Information Quarterly –The calculation of IF in JCR 2006 is indeed based on only a single year of data-. Two other journals Online and Econtent included in JCR and included in Scopus were not to be found in SCImago. This is not really a great miss, since these are trade journals rather than peer reviewed scholarly journals, but this applies to some other journals included in the table as well, e.g. The Scientist and Library Journal. In the end 50 journals from SCImago and JCR in the LIS field could be matched. The full list of journals included in this little study is linked as a Google Document.

Looking at the table it is apparent that the maximum value of SJR is an order of magnitude smaller than the impact Factors. At the lower en of the scale Impact factors become zero, whereas the lowest value of SJR in this set of journals is 0.038.
In Figure 1, I have plotted the IF against the SJR. There seems to be a strong relationship between SJR and IF, albeit there are some outliers from an apparent linear relationship. Interestingly these three outliers are LIS journals on medical librarianship, they are: Journal of the American Medical Informatics Association : JAMIA, Journal of Health Communication and Journal of the Medical Library Association. MIS Quarterly is not regarded as an outlier since it clear follows lies on the trendline underlying the other datapoints.

Figure 1

I think the three outliers really illustrate the point that SJR is more a pagerank type of indicator. The three medically oriented journals receive relatively citations from highly ranked medical journals. Checking this for JAMIA in Scopus, we find citations from journals such as Pediatrics (SJR=0.528), Annals of Internal Medicine (SJR= 1.127) or BMC Bioinformatics (SJR= 0.957). The journal adhering the trendline for LIS journals receive far less of these kind of “external” citations.

Excluding the three medical journals we get a very good regression between the two parameters with an R² of 0.86. In Figure 2 the regression line is added based on the remaining 47 journals.

Figure 2

Thought this is a really cool result illustrating the difference between SJR and IF quite clearly. In a subsequent post I will look a bit more into the correlations between the various parameters a bit more.

SJR : Scimago Journal & Country Rank

Sometimes you find these real gems. WoW, fantastic.

This evening I had this exciting feeling when I saw SJR for the first time. Tipped of by Recherchen Blog I stumbled upon Scimago. A database that provides a plethora of bibliometric indicators for journals and research performance at a country level. They have developed their own Pagerank (from Google) type of indicator for journal ranking called SJR indicator. But the data they provide is much more than only this indicator. Articles, citations and citations per article are provided as well.

This database is based on data provided by Scopus, which covers a much larger dataset than Journal Citation Reports or the Essential Science Indicators from Thomson Scientific. Very interesting to observe that SJR is freely available on the Web. This is a new development in the competition that is taking place between the two publishing giants Elsevier and Thomson.

The information contained in SJR is so overwhelming that it will take some time before I fully comprehend the possibilities of this database. To understand the new indicators and to make comparisons with the old established databases. The systems provides really nice graphics for journal data as well. The makers of SJR are really serious about their research, they recently published a study in Scientometrics some of their analyses with this database -on my pile of stuff to read-.

Noted some mention of SJR at Sidi and DigitalKoans as well. In the Spanish blogosphere the rumour has been spreading for some time already.

This database will certainly be covered in more detail at a later date.

Literature:
Moya-Anegón, F. d., Z. Chinchilla-Rodríguez, B. Vargas-Quesada, E. Corera-Álvarez, F. J. Muñoz-Fernández, A. González-Molina & V. Herrero-Solana (2007). Coverage analysis of Scopus: A journal metric approach. Scientometrics 73(1): 53-78. http://www.scimago.es/file.php?file=/1/Documents/CoverageScopus07.pdf