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
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 20 th 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
The most obvious example of this phenomenom is the works of Albert Einstein. 45 40 35 30 25 20 15 10 5 0 1905 1909 1913 1917 1921 1925 1929 1933 1937 1941 1945 1949 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. 1953 1957 1961 1965 1969 1973 1977 1981 1985 1989 1993 1997 2001 2005 Slide 3
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. 180 160 140 120 100 80 60 40 20 0 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Slide 4
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
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 500 400 300 200 100 0 1926 1933 1940 1947 1954 1961 1968 1975 Slide 6 1982 1989 1996 2003 Fiske CH Lineweaver, H Nelson, N Brunauer, S Moller, C
The first 3 articles, all of which have declining citation rates, are concerned with the determination of physical constants 500 400 300 200 100 However the last 2 articles 0 1926 1936 1946 1956 1966 1976 1986 1996 2006 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. Fiske CH Lineweaver, H Nelson, N Brunauer, S Moller, C 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
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. The article also outlines a method to calculate the surface area of solids such as powders or micro particles. There are many applications for this research, such as nanotechnology, pollution control and catalysis. 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. 400 350 300 250 200 150 100 50 0 1926 1933 1940 1947 1954 1961 1968 1975 1982 1989 1996 2003 Slide 8
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 0 2 4 6 8 10 12 14 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 Slide 9
Citing Subject Categories CHEMISTRY, PHYSICAL MATERIALS SCIENCE, MULTIDISCIPLINARY ENGINEERING, CHEMICAL ENVIRONMENTAL SCIENCES CHEMISTRY, APPLIED PHYSICS, APPLIED GEOCHEMISTRY & GEOPHYSICS CHEMISTRY, MULTIDISCIPLINARY NANOSCIENCE & NANOTECHNOLOGY 0 50 100 150 200 250 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
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 0 5 10 15 20 25 30 35 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
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 14% Use of Method 68% General Reference 18% Slide 12
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
Question 1 Where did you first hear about the article Adsorption of gases in multimolecular layers 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) Results 21% 22% 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 Slide 14
Question 2 How did you then locate a copy of the full text of the article? a. From an electronic full text archive b. From the print copy of the journal at my library c. From a colleague d. Through the internet e. Other (please specify in your answer) Results 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
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
Analysis of papers citing patents published in 1900 Later published papers citing patents published in 1900 were identified and analyzed by publication year 14 12 10 8 6 4 2 0 1901 1904 1909 1915 1922 1925 1929 1934 1939 1942 1947 1952 1956 1959 1962 1967 1970 1973 1976 1979 1982 1985 1988 1992 1997 2002 2005 No clear trend is observable Patents published in 1900 continue to be cited to the present day Slide 17
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 10 20 30 40 50 60 Slide 18
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 0 2 4 6 8 10 12 14 16 Slide 19
Example: 2005 published paper citing a 1900 patent Slide 20
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Patents citing papers published pre-1950; an example Slide 23
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 Slide 24
Thank you! Slide 25