Speaking of disciplines and normalization...

[Loet Leydesdorff]

Dear David, 
 
Now that I have read this more carefully, it seems to me that this
normalization is the same as the Mean Expected Citation Rate which the
Hungarian group uses already for two decades or so. As you correctly note,
they claim on p. 4 that "(t)he distribution of the relative indicator c/c(0)
is universal for all categories considered." These are two claims in one
sentence, notably, that they found it in the 172 ISI Subject Categories and
that this is universally true. If the latter is the case, one should be able
to prove this making simple assumptions about the distribution (e.g.,
Lotka). Is this true for any Lotka distribution?
 
The strict analogy with voting (footnote 18) suggests that scientists are
campaigning for citations. Perhaps, we should consider ads and commercials.
:-) Some of us already have been successful in making a business of citation
analysis! Note that the analogy with voting is different from a market
metaphor. Interesting.
 
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 Wojick
Sent: Thursday, October 23, 2008 12:33 PM
To: SIGMETRICS at LISTSERV.UTK.EDU
Subject: Re: [SIGMETRICS] Speaking of disciplines and normalization...



Indeed Loet, they appear to be claiming that the distribution has the same
form in all fields, differing only in height. A very strong claim. What does
it tell us about science?

Cheers, David


David Wojick, Ph.D., Senior consultant for innovation, DOE OSTI
http://www.osti.gov/innovation/


Oct 22, 2008 03:03:30 PM, SIGMETRICS at LISTSERV.UTK.EDU wrote:


Dear Christina, 
 
Thank you for noting this to the list. These authors use the 172 ISI Subject
Categories as an example, but their claim seems that however one divides the
total set into fields, rescaling to the mean for each subset does the job of
making results comparable because of the shape of the citation
distributions. 
 
The mathematicians among us are probably able to prove this. 
 
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 Pikas,  Christina K.
Sent: Wednesday, October 22, 2008 5:07 PM
To:  SIGMETRICS at LISTSERV.UTK.EDU
Subject: [SIGMETRICS] Speaking of  disciplines and normalization...


  
See this news  piece in Nature?
  
Published online  20 October 2008 | Nature | doi:10.1038/news.2008.1169
(http://www.nature.com/news/2008/081020/full/news.2008.1169.html)
  
News
Is physics  better than biology?
  
Citation  statistics now comparable across disciplines.
  
Philip  Ball
Is the physics department at your university performing better than the
biology department? Answering such questions objectively has been hard,
because citation statistics and other bibliometric indicators can't be
directly compared across disciplines. But now a team in Italy has found a
way  to do just that......
  
 
  

The full article isn't available at PNAS yet, but I  *think* this ArXiv
paper is the pre-print. Offered without commentary - I'll  let you all react
with shock and dismay (unless this has already appeared  here, in which
case, oops!)  :)

  

Universality of  citation distributions: towards an objective measure of
scientific  impact
Authors: Filippo Radicchi, Santo Fortunato, Claudio  Castellano
(Submitted on 5 Jun 2008)

  

     Abstract: We study the distributions of citations received by a single
publication within several disciplines, spanning all fields of science. We
show that the probability that a paper is cited $c$ times has large
variations  between different disciplines, but all distributions are
rescaled on a  universal curve when the relative indicator $c/c_0$ is
considered, where $c_0$  is the average number of citations per paper for
the discipline. In addition  we show that the same universal behavior occurs
when citation distributions of  papers published in the same field, but in
different years, are compared.  These findings provide a strong validation
of $c/c_0$ as an unbiased indicator  for citation performance across
disciplines and years. Based on this  indicator, we introduce a
generalization of the h-index suitable for comparing  scientists working in
different fields. 

  

Comments:  14  pages, 5 figures
Subjects:  Physics and Society (physics.soc-ph); Data  Analysis, Statistics
and Probability (physics.data-an)
Cite as:   arXiv:0806.0974v1 [physics.soc-ph]

  

Christina

  

Christina K. Pikas, MLS 
R.E. Gibson Library & Information Center
The Johns Hopkins  University Applied Physics Laboratory 
Voice  240.228.4812 (Washington),  443.778.4812 (Baltimore) 
Fax 443.778.5353 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.asis.org/pipermail/sigmetrics/attachments/20081023/ca45936d/attachment.html>