A Global Map of Science Based on the ISI Subject Categories -- preprint version available

[Loet Leydesdorff]

Dear David, 
 
Yes, we did so and it provided a nice presentation in 3D, for example, using
Kinetic Image. Unfortunately, this programme does not allow for labeling the
nodes nor for easy exportation in a standard format which can be included in
a Word file or the html. Thus, we decided not to use this representation,
but instead to use html for the mapping (at http://www.leydesdorff.net/map06
). 
 
Mathematics is embedded in the computer sciences and engineering. (A bit
also in physics.) If it would have had a strongly specific pattern (like not
citing or not being-cited) it would have come out as a factor. 
 
Best wishes, 
 
 
Loet
 
  _____  

Loet Leydesdorff 
Amsterdam School of Communications Research (ASCoR), 
Kloveniersburgwal 48, 1012 CX Amsterdam. 
Tel.: +31-20- 525 6598; fax: +31-20- 525 3681 
 <mailto:loet at leydesdorff.net> loet at leydesdorff.net ;
<http://www.leydesdorff.net/> http://www.leydesdorff.net/ 

 


  _____  

From: ASIS&T Special Interest Group on Metrics
[mailto:SIGMETRICS at LISTSERV.UTK.EDU] On Behalf Of David E. Wojick
Sent: Monday, October 22, 2007 4:30 PM
To: SIGMETRICS at LISTSERV.UTK.EDU
Subject: Re: [SIGMETRICS] A Global Map of Science Based on the ISI Subject
Categories -- preprint version available


Dear Loet, this is indeed interesting. Why did mathematics did not make the
14 factor cut, or is this explained in the paper? Is it that no one else
cites math?

Your 172 category network is clearly 3 dimensional. (My rule of thumb is
that if you cannot draw it without a lot of lines crossing then the topology
is 3D.) It might be useful to view it in 3D with rotation and zoom, to
better see the sub-structures. Have you considered this?

Best wishes,

David Wojick



A Global Map  <http://www.leydesdorff.net/map06/texts/index.htm> of Science
Based on the ISI Subject Categories

Loet Leydesdorff & Ismael Rafols

 <http://www.leydesdorff.net/map06/texts/map06.pdf> <click here for pdf>

 <http://www.leydesdorff.net/map06/index.htm> <click here for the maps>

The ISI subject categories classify journals included in the Science
Citation Index (SCI). The aggregated journal-journal citation matrix
contained in the Journal Citation Reports can be aggregated on the basis of
these categories. This leads to an asymmetrical transaction matrix (citing
versus cited) which is much more densely populated than the underlying
matrix at the journal level. Exploratory factor analysis leads us to opt for
a fourteen-factor solution. This solution can easily be interpreted as the
disciplinary structure of science. The nested maps of science (corresponding
to 14 factors, 172 categories, and 6,164 journals) are brought online at
http://www.leydesdorff.net/map06/index.htm. An analysis of interdisciplinary
relations is pursued at three levels of aggregation using the newly added
ISI subject category of "Nanoscience & nanotechnology." The journal level
provides the finer grained perspective. Errors in the attribution of
journals to the ISI subject categories are averaged out so that the factor
analysis can reveal the main structures. The mapping of science can,
therefore, be comprehensive at the level of ISI subject categories.

 
  _____  

Loet Leydesdorff
Amsterdam School of Communications Research (ASCoR)
Kloveniersburgwal 48, 1012 CX Amsterdam
Tel.: +31-20- 525 6598; fax: +31-20- 525 3681
loet at leydesdorff.net ; http://www.leydesdorff.net/

 
Now available: The
<http://www.universal-publishers.com/book.php?method=ISBN&book=1581129378>
Knowledge-Based Economy: Modeled, Measured, Simulated. 385 pp.; US$ 18.95 
The
<http://www.universal-publishers.com/book.php?method=ISBN&book=1581126956>
Self-Organization of the Knowledge-Based Society; The
<http://www.universal-publishers.com/book.php?method=ISBN&book=1581126816>
Challenge of Scientometrics

 
 
 

-- 

"David E. Wojick, PhD" <WojickD at osti.gov>
Senior Consultant for Innovation
Office of Scientific and Technical Information
US Department of Energy
http://www.osti.gov/innovation/
391 Flickertail Lane, Star Tannery, VA 22654 USA
540-858-3136

http://www.bydesign.com/powervision/resume.html provides my bio and client
list. 
http://www.bydesign.com/powervision/Mathematics_Philosophy_Science/ presents
some of my own research on information structure and dynamics. 

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