Question about ISI's SCI five year cumulations

[Garfield, Eugene]

Eugene Garfield, PhD. email garfield at codex.cis.upenn.edu
tel 215-243-2205   fax 215-387-1266
President, The Scientist   www.the-scientist.com
Chairman Emeritus, ISI  www.isinet.com
home page: www.eugenegarfield.org
Past President, American Society for Information Science and Technology
(ASIS&T)  www.asis.org





-----Original Message-----
From: Eric Ackermann [mailto:egackerma at RADFORD.EDU]
Sent: Sunday, March 14, 2004 11:52 AM
To: SIGMETRICS at LISTSERV.UTK.EDU
Subject: [SIGMETRICS] Question about ISI's SCI five year cumulations


Hi,

Apologies for cross-posting.

I am putting together a bibliometric study of the Polywater research
literature, 1962-1974. I need some benchmark values for various measures,
such
as citations per paper. My access to WOS only goes back to 1989, so I've
been
using the SCI's five year cumulations in print. In the first volume of each
cumulation is a page (usually around p. 17) called "Comparative Statistical
Summary." Herein lies my questions re: "Citations per Authored Items Cited".
1. Are the "authored items cited" the same as the research articles,
reviews,
and technical notes used by the SCI? NO
If not, what are they? ANY AUTHORED ITEM CITED, WHETHER COVERED OR NOT IN
SCI SOURCE COVERAGE. IT WOULD NOT INCLUDE ANONYMOUS ITEMS OR PATENTS.

2. There is an annual cumulation given for each of the five years, and then
one
for the entire five year block. The average values for "authored items
cited"
for the five year block are different for the average annual. For example,
for
1965-1969, the average for the annual cumulations is 1.65 + 1.65 + 1.66 +
1.67
+1.67 = 8.3/5years = 1.66. THIS IS SOMETIMES CALLED THE GARFIELD CONSTANT,
WHICH IS NOT A CONSTANT SO IT IS MORE PROPERLY THE GARFIELD RATIO. THE VALUE
SHOWN IS BASED ON CITATIONS RECEIVED IN ONE YEAR.
see my essay http://www.garfield.library.upenn.edu/essays/v2p419y1974-76.pdf
 Is the ratio between number of citations and publications cited a true
constant?

The average for the five year block is 2.55. Why the
difference? CITATIONS FOR A FIVE YEAR PERIOD are INCLUDED
3. For the annual cumulations, are these just total citation counts for that
year, YES

 or is there some sort of citation window (fixed or variable) involved? SEE
ABOVE

That's all for now! Many thanks for any help or insight you can give.

Regards,

Eric
--
Eric G. Ackermann
Reference/Instruction Librarian
McConnell Library
Radford University
PO Box 6881
Radford, VA  24142
Email: egackerma at radford.edu
Phone: 540-831-5688
http://lib.radford.edu/

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