Tag Archive for 'Scopus'

The Impact Factor of Open Access journals

Published on January 6, 2011 in Open Access. 17 Comments

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

Scopus is adding institute disambiguation

Published on December 14, 2007 in Databases. 0 Comments

Today it was announced that institute disambiguation, or the affiliation identifier, will become functional in Scopus early January 2008.  At this promotional site it is demonstrated what a search for the University of Liverpool returns in options of selection the right University of Liverpool and whether or not you want to include the teaching hospitals in a subsequent search as well.

Web of Science already included a refine option with an affiliation option amongst others, but they way the results are presented for Scopus shows that Elsevier has taken a different approach to solving this problem.

It will be interesting to test both approaches in more detail when the Scopus tool is officially launched.

Scopus is speeding up it’s indexing

Published on December 11, 2007 in Databases. 0 Comments

I knew it was coming, today I noted it for the first time that Scopus is already indexing and alerting ‘articles in press’ (or any of its variations such as ‘online first’). In one of my regular alerts I got this article from Henk Moed:

Moed, H.F. (2007) UK Research Assessment Exercises: Informed judgments on research quality or quantity? Scientometrics, pp. 1-9. Article in Press

SJR : Scimago Journal & Country Rank

Published on December 11, 2007 in Databases. 1 Comment

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

Reprise : Impact factors calculated with Scopus compared to JCR

Published on November 10, 2007 in Databases. 0 Comments

ResearchBlogging.org Did I report yesterday on the first preprint article that compared Impact factors calculated with JCR and Scopus, later that day a second journal was published on e-lis covering the same subject. Gorraiz and Schoegl (2007) took the analysis really a step further than Pislyakov (2007). Not only did they include a larger set of journals in their sample 100 compared to 20, they also looked at the other bibliometric indicator the immediacy index.

Interesting is the determination of the authors to look for journals in the chosen subject area, pharmacology, that were not included in the JCR but should have been there on the basis of their citations. In the journal selection process of Thomson some other factors are taken into account, but in practice we expect all top journals in a certain category to be included in the JCR/WoS database. So it is interesting to learn that there are a number of journals that should have been included on the basis of citation data in the databases of Thomson.

At the beginning of the article the authors state:

Since there are more journals included in Scopus than in WoS, a journal in Scopus has a higher cace to get cited in general. Therefore the the values for the impact factor and the immediacy index should also be higher in Scopus

This might sound plausible, but in actual fact the effect of a larger journal base is much smaller. Because Web of Science already covers virtually all top journals in the subject category they also cover the journals where most citations take place. Outside the top journals relatively little citation traffic takes place. This has been demonstrated by Ioannidis (2006) and is also indicated in journal selection policy of Thomson where they refer to some of their own research:

More recently, an analysis of 7,528 journals covered in the 2005 JCR® revealed that as few as 300 journals account for more than 50% of what is cited and more than 25% of what is published in them. A core of 3,000 of these journals accounts for about 75% of published articles and over 90% of cited articles.

What really is disturbing from both the articles of Gorraiz and Schoegl (2007) and Pislyakov (2007) is that both databases are not one hundred percent reliable when it comes to number of article published in a given year. For Scopus there we can expect some minor discrepancies since we are dealing with a young database that shows still some fluctuations in content. Elsevier still has some work to do. For WoS it is sometimes just sloppiness in indexing and that is unforgivable.

References:
Gorraiz, J. & C. Schloegl (2007). A bibliometric analysis of pharmacology and pharmacy journals: Scopus versus Web of Science. Journal of Information Science 00(00): 00-00. http://eprints.rclis.org/archive/00011966/
Ioannidis, J. P. A. (2006). Concentration of the Most-Cited Papers in the Scientific Literature: Analysis of Journal Ecosystems. PLoS ONE 1(1): e5. http://dx.doi.org/10.1371/journal.pone.0000005
Pislyakov, V. (2007). Comparing two “thermometers”: Impact factors of 20 leading economic journals according to Journal Citation Reports and Scopus. E-Lis. http://eprints.rclis.org/archive/00011865/

Impact factors calculated with Scopus compared to JCR

Published on November 9, 2007 in Databases. 1 Comment

You only had to wait for it. With the rich resource of citation data available in Scopus, somebody was going use it and calculate Impact Factors. Quantitative journal evaluations was once the single domain of Thomson Scientific (formerly ISI) but nowadays they face more and more competition. Elsevier, with Scopus, has so far hesitated to step into the arena of journal evaluation, but Vladimir Pislyakov (2007) has made a start for the 20 top journals in economics.
He compared the Impact factor from the JCR with the Impact he construed for the same journals with citation data from Scopus. In his methodology he made small mistake by not excluding the non citable items, which is quite easy to do in Scopus. But this will not invalidate his results. What was to be expected, confirming our experience with higher citations in Scopus compared to Web of Science, is that overall more citations per article were found in Scopus. This resulted in slightly higher IF as calculated by Scopus. What is more interesting is that the rankings of the journals based on Scopus data differed from the ranking based on the JCR impact factors. Overall they correlated well, but looking into detail, there was a journal that dropped from rank 5 to 13, another from 11 to 18. So there is merit to investigate this on a larger scale than those 20 journals in economics.
In the end the author makes a big mistake, he states

“Since impact factor is considered to be one of the crucial citation indicators which is widely used in research assessment and science administration, it is important to examine it critically from various points of view and investigate the environment in which it is calculated.”

Those are practices we should stay away from. The IF as such is only of interest for scientists when they select a journal for publication. IF should not be used for research evaluation of grant applications.

Reference:
Pislyakov, V. (2007). Comparing two “thermometers”: Impact factors of 20 leading economic journals according to Journal Citation Reports and Scopus. E-Lis. http://eprints.rclis.org/archive/00011865/

THES university rankings 2007

Published on November 6, 2007 in Scientometrics. 0 Comments

Next Friday the Times Higher Education Supplement will publish it’s famous rankings for world universities . This year they have changed the methodology quite a bit. Perhaps to counter some of the criticism on these rankings as formulated in the Wikipedia. They have made changes to the peer review, which counts for 40% in the overall ranking, and prevented the possibility of self selection of own universities by peers. They have changed the database from which they retrieve the citation data. They have selected Scopus from Elsevier above citation data from ISI (The Essential Science Indicators from Thomson Scientific that is). They have reduced the citation frame period, from ten to five years. They have attempted to make a difference between full time equivalents and number of faculty and finally they have normalized the rankings.

There are two items I like to pick out. They have selected Scopus over ESI. Quite a change. This will be less disadvantageous for countries with a strong publication culture in their own language. Think about France, Germany and all Spanish language countries, or perhaps Chinese, Japanse or Korean. The other aspect is the citation frame. I encourage a five year period over a 10 year period, but they only look at “the most recent complete 5 year window” , i.e. 2002-2006. Whereas I would prefer the period of 2001-2005 or even better 2000-2004, so all publications will have received their fair share of citations.

Meanwhile we remain, and wait for Friday to see how all these changes will affect these popular rankings.

Reference;

Sowter, B. (2007) THES – QS World University Rankings 2007. QS TopUniversities. http://www.topuniversities.com/news/article/thes_qs_world_university_rankings_2007_basic_explanation_of_key_enhancements_in_methodology_for_2/