3,984 research outputs found
A review of the literature on citation impact indicators
Citation impact indicators nowadays play an important role in research
evaluation, and consequently these indicators have received a lot of attention
in the bibliometric and scientometric literature. This paper provides an
in-depth review of the literature on citation impact indicators. First, an
overview is given of the literature on bibliographic databases that can be used
to calculate citation impact indicators (Web of Science, Scopus, and Google
Scholar). Next, selected topics in the literature on citation impact indicators
are reviewed in detail. The first topic is the selection of publications and
citations to be included in the calculation of citation impact indicators. The
second topic is the normalization of citation impact indicators, in particular
normalization for field differences. Counting methods for dealing with
co-authored publications are the third topic, and citation impact indicators
for journals are the last topic. The paper concludes by offering some
recommendations for future research
The concordance of field-normalized scores based on Web of Science and Microsoft Academic data: A case study in computer sciences
In order to assess Microsoft Academic as a useful data source for evaluative
bibliometrics it is crucial to know, if citation counts from Microsoft Academic
could be used in common normalization procedures and whether the normalized
scores agree with the scores calculated on the basis of established databases.
To this end, we calculate the field-normalized citation scores of the
publications of a computer science institute based on Microsoft Academic and
the Web of Science and estimate the statistical concordance of the scores. Our
results suggest that field-normalized citation scores can be calculated with
Microsoft Academic and that these scores are in good agreement with the
corresponding scores from the Web of Science.Comment: 10 pages, 2 figures, 1 tabl
Towards a new crown indicator: Some theoretical considerations
The crown indicator is a well-known bibliometric indicator of research
performance developed by our institute. The indicator aims to normalize
citation counts for differences among fields. We critically examine the
theoretical basis of the normalization mechanism applied in the crown
indicator. We also make a comparison with an alternative normalization
mechanism. The alternative mechanism turns out to have more satisfactory
properties than the mechanism applied in the crown indicator. In particular,
the alternative mechanism has a so-called consistency property. The mechanism
applied in the crown indicator lacks this important property. As a consequence
of our findings, we are currently moving towards a new crown indicator, which
relies on the alternative normalization mechanism
A review of the characteristics of 108 author-level bibliometric indicators
An increasing demand for bibliometric assessment of individuals has led to a
growth of new bibliometric indicators as well as new variants or combinations
of established ones. The aim of this review is to contribute with objective
facts about the usefulness of bibliometric indicators of the effects of
publication activity at the individual level. This paper reviews 108 indicators
that can potentially be used to measure performance on the individual author
level, and examines the complexity of their calculations in relation to what
they are supposed to reflect and ease of end-user application.Comment: to be published in Scientometrics, 201
Field-normalized citation impact indicators and the choice of an appropriate counting method
Bibliometric studies often rely on field-normalized citation impact
indicators in order to make comparisons between scientific fields. We discuss
the connection between field normalization and the choice of a counting method
for handling publications with multiple co-authors. Our focus is on the choice
between full counting and fractional counting. Based on an extensive
theoretical and empirical analysis, we argue that properly field-normalized
results cannot be obtained when full counting is used. Fractional counting does
provide results that are properly field normalized. We therefore recommend the
use of fractional counting in bibliometric studies that require field
normalization, especially in studies at the level of countries and research
organizations. We also compare different variants of fractional counting. In
general, it seems best to use either the author-level or the address-level
variant of fractional counting
A Review of Theory and Practice in Scientometrics
Scientometrics is the study of the quantitative aspects of the process of science as a communication system. It is centrally, but not only, concerned with the analysis of citations in the academic literature. In recent years it has come to play a major role in the measurement and evaluation of research performance. In this review we consider: the historical development of scientometrics, sources of citation data, citation metrics and the âlaws" of scientometrics, normalisation, journal impact factors and other journal metrics, visualising and mapping science, evaluation and policy, and future developments
Do altmetrics correlate with citations? Extensive comparison of altmetric indicators with citations from a multidisciplinary perspective
An extensive analysis of the presence of different altmetric indicators
provided by Altmetric.com across scientific fields is presented, particularly
focusing on their relationship with citations. Our results confirm that the
presence and density of social media altmetric counts are still very low and
not very frequent among scientific publications, with 15%-24% of the
publications presenting some altmetric activity and concentrating in the most
recent publications, although their presence is increasing over time.
Publications from the social sciences, humanities and the medical and life
sciences show the highest presence of altmetrics, indicating their potential
value and interest for these fields. The analysis of the relationships between
altmetrics and citations confirms previous claims of positive correlations but
relatively weak, thus supporting the idea that altmetrics do not reflect the
same concept of impact as citations. Also, altmetric counts do not always
present a better filtering of highly cited publications than journal citation
scores. Altmetrics scores (particularly mentions in blogs) are able to identify
highly cited publications with higher levels of precision than journal citation
scores (JCS), but they have a lower level of recall. The value of altmetrics as
a complementary tool of citation analysis is highlighted, although more
research is suggested to disentangle the potential meaning and value of
altmetric indicators for research evaluation
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