Archive for November, 2007

Reprise : Impact factors calculated with Scopus compared to JCR

Published on November 10, 2007 in Databases. 0 Comments

Blogging on Peer-Reviewed ResearchDid 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/

Leo Waaijers in Ariadne Magazine

Published on November 9, 2007 in Open Access. 0 Comments

Just announced in my Dutch blog that Leo Waaijers will give a presentation at the opening symposium of our brand new library. Then I received the TOC of this months Ariadne magazine in which Leo wrote the article “The DARE Chronicle: Open Access to Research Results and Teaching Material in the Netherlands. The article is an good recap of what is happening in the Netherlands related to OA developments, an good read for anybody interested in OA.

Other articles on OA related articles included in this issue of Ariadne are:
DRIVER: Building the Network for Accessing Digital Repositories across Europe
Further Experiences in Collecting Born Digital Archives at the Wellcome Library
Googlepository and the University Library

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/

About the header picture

Published on November 9, 2007 in Random. 4 Comments

The photo in the header is the street where we live. You can actually see our house, it is behind the completely brown cow. An old brick house, in a row of 4 houses, built in 1931 or thereabout. The photo has been taken from the floodplains of the Rhine. These are flooded on a regular basis. Between the cows and the street there is a small water which a kind of artificial creek.

Dutch universities in the Thes university rankings 2007

Published on November 8, 2007 in Scientometrics. 1 Comment

The Thes university rankings 2007 are now officially released. The ranking of Dutch universities is as follows with the overall rank in the THES top 200 and the previous ranking between brackets :

  1. University of Amsterdam 48(69)
  2. Delft 63(86)
  3. Leiden 84 (90)
  4. Utrecht 89(95)
  5. Maasstricht 111(172)
  6. Eindhoven 130(67)
  7. Wageningen 148(97)
  8. Erasmus 163(92)
  9. Groningen 173(232)
  10. Twente 185(115)
  11. Radboud 195(137)

All in all 11 out of 13 regular Dutch universities are enlisted in the top 200. In the case of the missing Free University I really wonder to what extend there might be a mix up of the two universities based in Amsterdam. For Tilburg it is rather unfortunate that they didn’t make it to the list but since Tilburg is mainly a humaniora and social sciences university it can be explained. As soon as I get more details, I will post more.

Dutch universities fall in the THES University rankings 2007

Published on November 8, 2007 in Scientometrics. 0 Comments

The first results of the THES universities rankings 2007 are already published on the Web, despite the embargo untill Friday. The change in methodology has quite a dramatic effect for the Dutch universities. Did we have an impressive 7 universities in the top 100 last year, in the 2007 edition only 4 remain in the top 100. Thee poll position of Dutch universities is taken over by UvA at 48 (up from 69), followed by Delft at 63 (up from 86), Leiden at 84 ( up from 90) and Utrecht at 89 (up from 89). The universities of Eindhoven, Rotterdam and Wageningen dropped out the top 100 from this league table.

It is too early to say what the exact cause of all these changes, then we should have a look at all parameters underlying this ranking. For that we have to await the official publication.

hattip: University Ranking Watch who has three stories on the new rankings, English and Canadian universities are doing exceptionally well according to URW

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/

WoW!ter.net : the scope of this blog

Published on November 5, 2007 in Blogging. 4 Comments

When I started blogging, I was heavily interested in developments with search engines and to a lesser extent in libraries, library systems or information science. In due course my attention shifted away from websearch. Not that I didn’t follow it, but it was really difficult to stay abreast of the avalanche of information on this subject. Since September 2005 the onset of web 2.0 and the role of web 2.0 in librarianship has become one of the recurring memes on my Dutch blog. This meme will return on this blog for sure. I will attempt to point out to the rest of the world what is happening in the Dutch library world with respect to innovative library developments. Let them be 2.0 or 3.0 or whatever.
Another theme that has my sincere interest is the review and comparison of new developments of library systems, either library content management systems or article and Indexing databases. The review of these developments will take place here, rather than on my Ducht blog. I assume that for most of the (Dutch) academic librarians the language thing won’t be a problem too much.
Another recurrent theme on my Dutch blog is the development of the Duch Biblioblogosphere. That subject is not likely to be covered here in a similar way, but development of the blogosphere as such is a subject that has my interest that will receive some attention.
Last but not least another of my hobby horses is scientometrics. Research evaluation based on bibliometrics.

The first post on this blog : The language thing revisited 2

Published on November 5, 2007 in Blogging. 4 Comments

The parallel blog to this blog was started in May 2005. From the onset it was a blog written in Dutch. At the beginning I thought it was more important to plough back information from the English library log world into the Dutch biblioblogosphere. However it soon proved interesting to post in English as well. I felt a strong need to interact with the English liblog world as well. So for some period of time my blog at wowter.nl was bilingual.
The title of this post refers back to a discussion –in blogs- I had with Ruminations and In between. Interesting to note how my opinion has changed now. Since it seems to me that you can’t really combine two languages on a single blog. In the end a bilingual blog proved to be unsatisfactory. I had the feeling the blog was becoming less attractive to a part of my Dutch Audience. Posts in English were visited less frequently than Dutch posts. On the other hand, being primarily a Dutch, or bilingual Blog It seemed to me that I did not attract a steady English speaking audience. This is also affected by the observation that a mainly Dutch blog will rank less favourable in Google.com, so the discoverability of the English blog posts was far lower than Dutch post by Google.nl.
So for quite some time I had the idea to circumvent all these problems and start a separate blog in English, on a more international domain. I registered wowter.net already quite some time ago, but I never got around to make a start. I finally didn’t bother too much about a super perfect layout and here it is.
I finally made the start.