Corresponding author: Joakim Philipson (
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This article explores the possibility of promoting knowledge export by means of citation function indexing. Instances of knowledge export are exemplified by cross-disciplinary citations, which, it is suggested, may indicate a prolonged life time use of documents.
To promote cross-disciplinary knowledge export by means of improved indexing of citation functions the examples of long "sleeping beauties" and the "princes" finally awakening them from their slumbers should be analyzed thoroughly. The results of this analysis might be useful to render CiTO more specific and targeted to the goal of serving as a scientific discovery tool. Citation function indexing terms should be combined with domain specific subject headings to make the cross-disciplinary coupling of research areas complete.
Citations can often be seen as observable results of a transfer of knowledge, as records of used information. Citations as a potential measure of relevance was noted at least implicitly by
Still, why is it that certain documents are being found relevant for the most various purposes over and over again long time after their publication, while others tend to fall into oblivion only a few years after their appearance. Which factors are involved in distinguishing the potentially long-lived cited document from the less successful, more short-lived ones?
Apart from the phenomenon of sleeping beauties, citation analyses have shown substantial variations in citation patterns over time from one discipline to another. There are indications e.g. that documents within the social sciences continue to be cited for a longer period of time than what is the case for the natural sciences
Another example is that of
Still, most articles published in
Understanding the multipurposeness of scientific papers and their potential for knowledge export calls for an explanation of the function that the cited source fulfils in the context of the citing documents. How does the cited information fit into this sometimes completely new disciplinary environment? In this paper we examine a few examples of cross-disciplinary citation functions, to see if they could also be expressed by the emerging standard citation typing ontology
Most citation analysis studies so far have been quantitative. Citation counts have been made, e.g, in order to identify the core literature of a scientific discipline and co-citation clustering has been used for mapping the structure of scientific disciplines
Since then qualitative or
The earlier classification schemes for citation functions relied essentially on manual citation analysis of relatively small sets of articles (typically 10 to 100 items), while later attempts have been made to use semi-automated or computational methods for citation classification of larger samples of full-text articles. An overview of these attempts is found in
However, automated methods for citation classification, relying on explicit signals or cue words for identification of citation functions
The main objective of this proposal is to find ways to promote cross-disciplinary scientific knowledge export. One way of doing this is to find and describe the functions of citations in real cross-disciplinary use cases. A second step is then to find corresponding citation functions if any in
What follows are some selected examples of citations of papers from the field of atmospheric chemistry or stratospheric ozone monitoring
"Similar long-term trends are to be found in total column ozone measurements.... London and Kelley (1974) examining global total ozone found an increase in both the Northern and the Southern Hemisphere during the 1960s."
This article had at the time of access no shared subject descriptors with the cited document
"the long-term trend in stratospheric water and its similarity to the long-term trend in stratospheric ozone suggest that these changes arise from long-term changes in the intensity of the circulation." Mastenbrook and Oltmans (1983):2164
But obviously, the article is not
"Good estimates of the present stratospheric distribution of ozone and subsequent UV radiation are known (Koller, 1952; Dütsch, 1969; Cutchis, 1974). The total amount of ozone in the northern hemisphere is maximal in spring and minimal in fall. ... It is suggested that among flowering plants of the northern hemisphere, many of which have white or yellow flowers (Table 2), there has been convergent evolution in floral UV absorption. Yellow and white flowers are high in flavonoid pigments which strongly absorb UV light. The seasonality of UV radiation may be one major selective pressure. Yellow and white flowers comprise as much as 85% of an arctic flora (Kevan, 1972)."
Discerning some of the more important of premisses involved in the inference leading to the hypothesis in the third sentence of the extract, there is first the observation of the seasonal variation of stratospheric ozone and the subsequent seasonal variation of ultraviolet radiation reaching the earth, leading to a spring maximum of stratospheric ozone and a subsequent spring minimum of UV-radiation in the northern hemisphere (since stratospheric ozone absorbs UV-radiation). Then there is the knowledge that yellow and white flowers are strong absorbants of UV-radiation. Finally there is the evidence of the predominance of yellow and white flowers in the northern hemisphere. Together these premisses make probable the hypothesis that UV-absorption ability has acted as a selective evolutionary mechanism for flowers in the northern hemisphere. It is important to note here that the different premisses come from different subject areas. The first three cited sources in the extract belong to geophysics or climatology, whereas
"Stratospheric ozone depletion, accompanied by increases in ambient, biologically destructive ultraviolet-B radiation,104 may exacerbate the effect of climate change on infectious diseases. Arising from a different anthropogenic process than climate change, ozone destruction is occurring primarily from reactions between ozone and halogen free radicals derived from chlorofluorocarbons, other halocarbons, and methyl bromide."105
No specific object property was found in CiTO for citations referring to a likely cause, mechanism or explanatory force. A significant difference between the
"Total ozone data were previously analyzed by a number of authors including Angell and Korshover (1973), London and Kelly [sic!] (1974) with particular interest in quantifying long-term trends. The statistical procedure commonly used in these studies is linear regression analysis (i.e. fitting a straight line) applied to adjusted total ozone values (e.g. deviations from monthly means ...). However, problems arise in the interpretation of results from these linear regression models since these models fail to take account of the positive autocorrelation that is present in the ozone data. Hence, we consider time series analysis that accounts for autocorrelation in a quantitative trend assessment of ozone data."
In CiTO, the object property relating to method presupposes that the cited method is actually used by the citing document,
"Ophtalmologists working in equatorial regions have long been familiar with the syndrome of solar conjunctivo-keratopathy. [Description of symptoms follows.] ... A new factor has now arisen which threatens significantly to increase this hazard and possibly to extend the geopgraphical area in which this minor but apparently incurable syndrome may be encountered. It is the purpose of this note to bring the new circumstances to the attention of ophtalmologists. The new factor is the growing threat to the ozone layer from the ever-increasing quantities of chlorofluoromethane gases released into the atmosphere, mainly from aerosol sprays....
Again, there seems to be no directly corresponding object property in CiTO for this type of citation function expressing the motivation for or purpose of a research paper. A more general CiTO property that could be used to cover also cases like this is perhaps
"Recent studies by Cicerone (4) and
Cito has an object property
Now, as we have seen, not all the above examples of citation functions are directly translatable into CiTO object properties, but they nevertheless shed some light on the use of scientific information outside the discipline whence it originated. Possibly other, even more compelling examples such as these can be found, where the age distance between cited and citing documents is larger, as we already saw in section 1 for
Could citation indexing with
We have seen some instances of cross-disciplinary citations characterized by the kind of
Structural (or
The limited importance of topic matching relationships in citations was confirmed in a study by
There are no doubt also numerous instances of scientists not being aware of the potential relevance to their own work of the research performed by scientists within other subject areas, simply because they do not know, let alone refer to the literature of those subject areas. A possible case in point and an example of the fruitfulness in crossing disciplinary barriers for the production of new knowledge is provided by
Indexing citation functions is not so much about representing mental models or capturing the original intention of the citing author
"that a partial explanation behind the sudden awakening of top SBs may lie in the fact that the paper in question is suddenly “discovered” as relevant by an entire community in another discipline." ... and making the observation that top Sleeping Beauties "are characterized by a typically very high fraction of citations from other disciplines: for about 80% of the top SBs, as much as 75% or more of citations are of interdisciplinary nature."
Next step would be then to have a panel of independent researchers from the same field as the
The resulting indexing scheme of a conclusive test should be sufficiently easy to use, so that virtually anyone who reads and writes and cites would be able to contribute to the indexing effort. Online publishers of scientific journals, managers of digital repositories like JSTOR and existing citation indexes like the Web of Science and CiteSeerX could make it happen by means of crowd-sourcing from the users. Ideally, tagging a scientific article online with citation functions from a controlled index language should be just little more complicated than liking a post on social media.