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S C I E N T I F I C
S O L U T I O N S
An analysis of citations in scientific and patent literature to historical
research from the first half of the 20th century and the relationship to
the accessibility of these works through electronic archives
Simon M Pratt & Robert A Stembridge
S C I E N T I F I C
S O L U T I O N S
• The Web of Science and previous versions of the Science Citation
Index (SCI, SciSearch) have long been considered the standard for
bibliometrics and the analysis of citations for research evaluation
• The introduction of a new archive, called the Century of Science, has
extended the retrospective coverage of the Web of Science for the
period 1900 to 1944.
• This has made it possible to comprehensively analyze the citations to
historic works of the early part of the 20th century, a so called golden
era for scientific discovery, especially in the field of theoretical
chemistry and physics.
• There are several very highly cited works in this period, and many of
these are being more heavily cited today than at any time in their
history.
Slide 2
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• The most obvious example of this phenomenom is the works of Albert
Einstein.
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• As can be seen by this diagram showing citations to Einstein’s 1905
paper on the Special Theory of relativity, the number of citations per
year has increased dramatically in the last 10 years or so.
Slide 3
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• This trend is a direct contradiction to the expected trend for the journal
that this article was published in, Annalen Der Physik. A comparison
with the citation trend for all articles published in the same journal
between 1900 and 1904 shows this clearly.
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• There are several logical explanations for this trend such as:
– Research in that particular field has not yet reached a satisfying
conclusion, and the research is still valid in the modern era
– The theories discussed in the article are so revolutionary that it takes
sometime before they can be understood and utilized by the larger
research community
– Historical reasons; in this case 2005 was the 100 year anniversary of the
publication of the article and the 50 year anniversary of Einstein's death
– Increased visibility and accessibility to Einstein’s work has led to
researchers re-discovering long forgotten works
• We believe that all of these are contributing factors to the increasing
rate of citations.
Slide 5
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• Not all articles follow the same trend.
• We can see a good example of this when we compare the 5 mostly
highly cited articles in the Century of Science
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Fiske CH
Lineweaver, H
Nelson, N
Brunauer, S
Moller, C
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Copyright 2006 Thomson
S C I E N T I F I C
• The first 3 articles, all of
which have declining
citation rates, are concerned
with the determination of
physical constants
S O L U T I O N S
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Fiske CH
Lineweaver, H
Nelson, N
Brunauer, S
Moller, C
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• However the last 2 articles
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are more interesting.
They show and increase in citations in the last 10 years that far
exceeds their historic citation rates. A quick inspection of their titles
shows that they would appear to be relevant to current research.
Brunauer, S; Emmett, PH; Teller, E
Adsorption of gases in multimolecular layers
Moller, C; Plesset, MS
Note on an approximation treatment for manyelectron systems
Slide 7
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• The Stephen Brunauer, Paul Hugh Emmett and Edward Teller article
outlines the BET theory of gas absorption which is commonly used by
many researchers today.
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• There are many applications for
this research, such as nanotechnology, pollution control and
catalysis.
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• The article also outlines a
method to calculate the
surface area of solids such as
powders or micro particles.
• By limiting the 6,700 citing articles to just those published in 2005-2006
(618 articles), we can further analyze the results to find out how this
article is being cited now.
Slide 8
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Citing Institutes
CNRS, France
KOREA RES INST CHEM TECHNOL, South Korea
UNIV MONTPELLIER 2, France
UNIV EXTREMADURA, Spain
TIANJIN UNIV, Peoples R China
CSIC, Spain
UNIV BOLOGNA, Italy
UFRGS, Brazil
TOKYO INST TECHNOL, Japan
OAK RIDGE NATL LAB, USA
NATL ACAD SCI UKRAINE, Ukraine
MARIE CURIE SKLODOWSKA UNIV, Poland
KOREA ADV INST SCI & TECHNOL, South Korea
DELFT UNIV TECHNOL, Netherlands
CNR, Italy
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• The citing articles are very international in scope, signifying that this
article is very well known throughout the scientific community, as would
be expected for an article of this age
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Citing Subject Categories
CHEMISTRY, PHYSICAL
MATERIALS SCIENCE, MULTIDISCIPLINARY
ENGINEERING, CHEMICAL
ENVIRONMENTAL SCIENCES
CHEMISTRY, APPLIED
PHYSICS, APPLIED
GEOCHEMISTRY & GEOPHYSICS
CHEMISTRY, MULTIDISCIPLINARY
NANOSCIENCE & NANOTECHNOLOGY
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• Nothing surprising here; these are the fields that you would expect for an
article dealing with gas absorption and surface area of micro particles
• Note the absence of History & Philosophy of Science, signifying that this article
is not being cited because of its historic significance (different to Einstein)
Slide 10
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Citing Journals
JOURNAL OF COLLOID AND INTERFACE SCIENCE
MICROPOROUS AND MESOPOROUS MATERIALS
JOURNAL OF PHYSICAL CHEMISTRY B
LANGMUIR
GEOCHIMICA ET COSMOCHIMICA ACTA
JOURNAL OF MATERIALS CHEMISTRY
CHEMISTRY OF MATERIALS
JOURNAL OF FOOD ENGINEERING
ENVIRONMENTAL SCIENCE & TECHNOLOGY
COLLOIDS AND SURFACES A-PHYSICOCHEM
APPLIED CATALYSIS A-GENERAL
JOURNAL OF HAZARDOUS MATERIALS
CARBON
INDUSTRIAL & ENGINEERING CHEMISTRY RES
APPLIED SURFACE SCIENCE
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• Again there are no surprises here which further supports the idea that citations
to this article are not any kind of anomaly, or that it is being cited for reasons
other than the impact of this article on current research
Slide 11
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
• By looking at 22 of the most recent citing articles, and studying the
context of the citations it can be seen that there are 3 general
variations on the context of the citation.
– “Historical Reference” - e.g. “The BET model extends the Langmuir
model” these are often cited in the introduction
– “Use of Method” - e.g. “Surface areas were estimated according to the
BET model”
– “General reference” : referring to an element of the original article and
building upon that work
Of the 22 citing articles that were studied:
– Historical Reference
– Use of Method
– General Reference
14%
68%
18%
Slide 12
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Survey
• We conducted a short survey of researchers who cited the article
within the last year.
• Sent 200 e-mails, and received 72 replies (much higher than expected)
• The respondents were very international with replies from all
geographic regions including some unexpected places such as
Morocco
• Respondents were primarily academics, but several from government
and corporate research too
Slide 13
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Question 1
•
Where did you first hear about the article
“Adsorption of gases in multimolecular layers”
Results
a. Through a colleague
b. I have always known about this article /
It is so long ago that I forget
c. From a web search
d. From a bibliographic database
e. From a reference in another article or book
f. Other (please specify in your answer)
– 21%
– 22%
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1%
1%
50%
4%
Of those that said “Other” all of them reported that they had first heard
of this article as part of an academic course
Interesting Quote “Actually, I read about it when I was a graduate
student, in the 1950s”
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Question 2
•
How did you then locate a copy
of the full text of the article?
a.
b.
c.
d.
e.
Results
From an electronic full text archive
From the print copy of the journal at my library
From a colleague
Through the internet
Other (please specify in your answer)
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–
–
–
–
15%
51%
19%
4%
10%
Of those that said “Other” most had read translations of the article
available in local language books
Interesting quote “for this article the full text was not retrieved. It
simply is used to report the method used by the software of our
surface area analysis instrument.”
Slide 15
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Question 3
•
Aside from the historical perspective of this article,
how relevant is it to your research now?
a. very relevant
b. Somewhat relevant
c. not relevant, only of historical interest
Results
– 54%
– 32%
– 14%
Clearly this historic research published in 1938 is still relevant to
research today
Interesting quote “The BET method is still used to analyze adsorption
isotherms but is being replaced (somewhat) by DFT methods”
Slide 16
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Analysis of papers citing patents published in 1900
• Later published papers citing patents published in 1900 were identified
and analyzed by publication year
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• No clear trend is observable
• Patents published in 1900 continue to be cited to the present day
Slide 17
Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Citing subject categories
Chemistry, Multidisciplinary
Chemistry, Applied
Chemistry, Physical
Chemistry, Organic
Metallurgy & Metallurgical Engineering
Engineering, Electrical & Electronic
Chemistry, Analytical
Polymer Science
Engineering, Chemical
Electrochemistry
Multidisciplinary Sciences
Imaging Science & Photographic Technology
Biochemistry & Molecular Biology
Materials Science, Multidisciplinary
Materials Science, Ceramics
0
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S C I E N T I F I C
S O L U T I O N S
Citing journals
INDUSTRIAL AND ENGINEERING CHEMISTRY
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
CHEMICAL REVIEWS
ZEITSCHRIFT FUR ELEKTROCHEMIE
PROCEEDINGS OF THE IEEE
JOURNAL OF ORGANIC CHEMISTRY
BERICHTE DER DEUTSCHEN CHEMISCHEN
GESELLSCHAFT
USPEKHI KHIMII
PHOTOGRAPHIC SCIENCE AND ENGINEERING
JOURNAL OF INDUSTRIAL AND ENGINEERING
CHEMISTRY-US
BULLETIN DE LA SOCIETE CHIMIQUE DE FRANCE
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S C I E N T I F I C
S O L U T I O N S
Example: 2005 published paper citing a 1900 patent
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S C I E N T I F I C
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Patents citing papers published pre-1950; an example
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Conclusions
• Some classic historic research is increasingly heavily cited
• Analysis of the citing material suggests that the citations to the work are
genuine and are not any kind of anomaly or historical study
• A survey of citing authors shows that
– The majority found this article from a cited reference of bibliography of another
work, Web Searching does not seem to have played a major role in the awareness
of this article.
– The majority of researchers still access the full text of this article via the print
journal, this may reflect a lack of access to the electronic copy
– The majority of researchers still believe that this work is relevant to their research
• A citation analysis of the relationship between patents and articles shows that
historic patents are also still being cited, but there is no clear evidence of an
increasing citation rate
• Citations from patents to articles, and from articles to patents can reveal
valuable information and should not be ignored.
• Retrospective coverage of both journals and patents is valuable to current
research
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Copyright 2006 Thomson
S C I E N T I F I C
S O L U T I O N S
Thank you!
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Copyright 2006 Thomson