Page 131 - Journal of Library Science in China, Vol.45, 2019

130 Journal of Library Science in China, Vol.11, 2019

4.1 Differences in feature distributions between citation content of books and non-specific
types of references

(1) Citation location
According to the location distributions of books in the citing literatures, books in computer
science, medicine and sport science get relatively high proportions in the Introduction section
(29.79%, 21.89%, and 13.79%). M.Y. Zhang et al. (2016) conducted location statistics on 5,320
citation data in 6 different disciplines of the PLoS One journal. The results showed that there
were 2,318 citations in the Introduction section, accounting for 43.57%. This suggested that
authors cited references more in the Introduction section, but there were some differences between
citation locations of books and non-specific types of references. Sombatsompop et al. (2006) have
annotated the locations of 300 articles in the field of clinical medicine. They found that 51.8% of
the citations appeared in the Results and Discussions section, followed by the Introductions section
(accounting for 42.7%. In fact, Sombatsompop’s definition of the Introduction section in their
paper covered Introduction and Related Work). The statistical results of 94 books in medicine in
this paper show that most citation locations are in Discussion (accounting for 51.42%), followed
by Introduction and Related Work (accounting for 27.41%). It indicates that in medicine, there is
a certain degree of similarity between books and non-specific types of references in the citation
location.
(2) Citation intensity
Hu (2014) analyzed the citation intensities of 350 articles in JOI, and the results showed that
the distributions of citation intensity followed the negative power law, and the average citation
intensity of each journal paper was about 1.5. The citation intensities of most books were
distributed between 1 and 2, while the distributions of high citation intensity were obviously
different in different disciplines. C.Z. Zhang et al. (2017) used the citation content in the full-texts
of 39 academic monographs in biomedicine and life sciences, engineering and computer science
as the data source. They investigated the citing behaviors of academic monographs from the
perspective of citation content characteristics, and found that in most academic monographs, the
ratios of citation content to references were concentrated between 1 and 1.5, which were close to
the results of this paper.
(3) Citation length
Based on the statistical analysis of the length of citation content, we found that citation content
about the books in the five disciplines were concentrated between 20-160 strings. Although
authors of different disciplines had different writing preferences, the distributions of citation
content lengths among disciplines were relatively close. C. Lu and C.Z. Zhang (2014) calculated
the citation lengths of 600 academic articles in the field of Library and Information Science, and
found that the average citation lengths of academic articles were mainly distributed between 50
and 200 strings, which were similar to the research results of this paper.