CWTS Journal Indicators

[Éric Archambault]

Dear Nees Jan

Thank you for this addition to the growing list of journal indicators. Having a publicly accessible list of scores like this is really important and will play an important role in the debate on journal impact. Having rigorous researchers such as the ones at CWTS pursuing this project initiated by Michel Zitt and Henry Small and pursued by Moed is certainly useful.

However, I feel this is still at the stage of a research project and we should be careful to characterize our indicators carefully before telling the wider community that they are ready for prime time. We can't afford to have any more flaky journal impact indicators. This is now the forth proposition for such an indicator, after the Journal Impact Factor, the Scimago indicator, and the Eigenfactor. In this context, allowing both practitioners and users to decide which one seems to have the greatest scientific merit is essential. This requires that the methods and all ingredients be known to users and practitioners. Your paper is useful to understand the recipe but some ingredients are missing from the public disclosure and these need to be made public to help the community characterize your tool.

In particular, I think a few more details on the methods would be useful here. Firstly, having more details about the bootsrapping method that you use to compute the stability intervals would be welcome. Have you written a paper on this technique? Secondly, an additional column with the field of each journal would be more transparent and useful to users.

Do you have an explanation for this behavior:
The Journal of Engineering Education is one of the source journals with the highest SNIP in 2008. Is this an artifact or in 2008 the journal became that good compared to 2007? I find the jump surprising as it is outside the boundaries that you calculated. Of course, it is not impossible by chance to fall outside these, just that the jump is somewhat large.

Kind regards

Eric

Source title

Source type

Print ISSN

Year

P

SNIP

SNIP (lower bound)

SNIP (upper bound)

% self cit

Journal of Engineering Education

Journal

1069-4730

2002

207

7.901979

6.625

9.355

16%

Journal of Engineering Education

Journal

1069-4730

2003

215

6.587213

5.393

7.838

11%

Journal of Engineering Education

Journal

1069-4730

2004

194

9.710727

7.719

11.838

9%

Journal of Engineering Education

Journal

1069-4730

2005

133

2.498504

1.685

3.463

48%

Journal of Engineering Education

Journal

1069-4730

2006

111

4.458215

3.042

6.121

16%

Journal of Engineering Education

Journal

1069-4730

2007

98

6.650165

4.437

9.274

23%

Journal of Engineering Education

Journal

1069-4730

2008

93

20.62702

14.286

28.396

10%

Journal of Engineering Education

Journal

1069-4730

2009

75

15.92148

12.191

20.305

16%

Journal of Engineering Education

Journal

1069-4730

2010

77

16.12523

12.181

20.454

14%

Journal of Engineering Education

Journal

1069-4730

2011

76

16.1012

11.783

21.15

14%

Journal of Engineering Education

Journal

1069-4730

2012

90

12.49939

9.933

15.098

7%



From: ASIS&T Special Interest Group on Metrics [mailto:SIGMETRICS at LISTSERV.UTK.EDU] On Behalf Of Nees Jan van Eck
Sent: September-25-13 10:09 AM
To: SIGMETRICS at LISTSERV.UTK.EDU
Subject: [SIGMETRICS] CWTS Journal Indicators

The 2012 SNIP values have been released on CWTS Journal Indicators (www.journalindicators.com<http://www.journalindicators.com>). SNIP (source normalized impact per paper) is a freely available journal impact indicator that uses a source normalization mechanism to correct for differences in citation practices between fields of science. Compared with the journal impact factor, SNIP allows for more accurate comparisons between journals active in different scientific fields. SNIP is calculated by CWTS based on Elsevier's Scopus database. With the release of the 2012 SNIP values, stability intervals have been added to CWTS Journal Indicators. These intervals indicate the reliability of the SNIP value of a journal. For instance, if a journal's SNIP value is largely due to a single very highly cited publication, this is indicated by a wide stability interval. SNIP is the only freely available journal impact indicator that is presented with stability intervals.

Your feedback on CWTS Journal Indicators is greatly appreciated.

Best regards,
Nees Jan van Eck

========================================================
Nees Jan van Eck PhD
Researcher
Head of ICT

Centre for Science and Technology Studies
Leiden University
P.O. Box 905
2300 AX Leiden
The Netherlands

Willem Einthoven Building, Room B5-35
Tel:       +31 (0)71 527 6445
Fax:       +31 (0)71 527 3911
E-mail:    ecknjpvan at cwts.leidenuniv.nl<mailto:ecknjpvan at cwts.leidenuniv.nl>
Homepage:  www.neesjanvaneck.nl<http://www.neesjanvaneck.nl/>
VOSviewer: www.vosviewer.com<http://www.vosviewer.com/>
========================================================

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