653 research outputs found
Betweenness and Diversity in Journal Citation Networks as Measures of Interdisciplinarity -- A Tribute to Eugene Garfield --
Journals were central to Eugene Garfield's research interests. Among other
things, journals are considered as units of analysis for bibliographic
databases such as the Web of Science (WoS) and Scopus. In addition to
disciplinary classifications of journals, journal citation patterns span
networks across boundaries to variable extents. Using betweenness centrality
(BC) and diversity, we elaborate on the question of how to distinguish and rank
journals in terms of interdisciplinarity. Interdisciplinarity, however, is
difficult to operationalize in the absence of an operational definition of
disciplines, the diversity of a unit of analysis is sample-dependent. BC can be
considered as a measure of multi-disciplinarity. Diversity of co-citation in a
citing document has been considered as an indicator of knowledge integration,
but an author can also generate trans-disciplinary--that is,
non-disciplined--variation by citing sources from other disciplines. Diversity
in the bibliographic coupling among citing documents can analogously be
considered as diffusion of knowledge across disciplines. Because the citation
networks in the cited direction reflect both structure and variation, diversity
in this direction is perhaps the best available measure of interdisciplinarity
at the journal level. Furthermore, diversity is based on a summation and can
therefore be decomposed, differences among (sub)sets can be tested for
statistical significance. In an appendix, a general-purpose routine for
measuring diversity in networks is provided
The substantive and practical significance of citation impact differences between institutions: Guidelines for the analysis of percentiles using effect sizes and confidence intervals
In our chapter we address the statistical analysis of percentiles: How should
the citation impact of institutions be compared? In educational and
psychological testing, percentiles are already used widely as a standard to
evaluate an individual's test scores - intelligence tests for example - by
comparing them with the percentiles of a calibrated sample. Percentiles, or
percentile rank classes, are also a very suitable method for bibliometrics to
normalize citations of publications in terms of the subject category and the
publication year and, unlike the mean-based indicators (the relative citation
rates), percentiles are scarcely affected by skewed distributions of citations.
The percentile of a certain publication provides information about the citation
impact this publication has achieved in comparison to other similar
publications in the same subject category and publication year. Analyses of
percentiles, however, have not always been presented in the most effective and
meaningful way. New APA guidelines (American Psychological Association, 2010)
suggest a lesser emphasis on significance tests and a greater emphasis on the
substantive and practical significance of findings. Drawing on work by Cumming
(2012) we show how examinations of effect sizes (e.g. Cohen's d statistic) and
confidence intervals can lead to a clear understanding of citation impact
differences
Metrics to evaluate research performance in academic institutions: A critique of ERA 2010 as applied in forestry and the indirect H2 index as a possible alternative
Excellence for Research in Australia (ERA) is an attempt by the Australian
Research Council to rate Australian universities on a 5-point scale within 180
Fields of Research using metrics and peer evaluation by an evaluation
committee. Some of the bibliometric data contributing to this ranking suffer
statistical issues associated with skewed distributions. Other data are
standardised year-by-year, placing undue emphasis on the most recent
publications which may not yet have reliable citation patterns. The
bibliometric data offered to the evaluation committees is extensive, but lacks
effective syntheses such as the h-index and its variants. The indirect H2 index
is objective, can be computed automatically and efficiently, is resistant to
manipulation, and a good indicator of impact to assist the ERA evaluation
committees and to similar evaluations internationally.Comment: 19 pages, 6 figures, 7 tables, appendice
Generating clustered journal maps: an automated system for hierarchical classification
Journal maps and classifications for 11,359 journals listed in the combined
Journal Citation Reports 2015 of the Science and Social Sciences Citation Indexes are
provided at https://leydesdorff.github.io/journals/ and http://www.leydesdorff.net/jcr15. A
routine using VOSviewer for integrating the journal mapping and their hierarchical clusterings
is also made available. In this short communication, we provide background on the
journal mapping/clustering and an explanation about and instructions for the routine. We
compare journal maps for 2015 with those for 2014 and show the delineations among fields
and subfields to be sensitive to fluctuations. Labels for fields and sub-fields are not provided
by the routine, but an analyst can add them for pragmatic or intellectual reasons. The
routine provides a means of testing one’s assumptions against a baseline without claiming
authority; clusters of related journals can be visualized to understand communities. The
routine is generic and can be used for any 1-mode network
Initial test of a Bayesian approach to solar flare prediction
A test of a new Bayesian approach to solar flare prediction (Wheatland 2004a)
is presented. The approach uses the past history of flaring together with
phenomenological rules of flare statistics to make a prediction for the
probability of occurrence of a large flare within an interval of time, or to
refine an initial prediction (which may incorporate other information). The
test of the method is based on data from the Geostationary Observational
Environmental Satellites (GOES), and involves whole-Sun prediction of soft
X-ray flares for 1976-2003. The results show that the method somewhat
over-predicts the probability of all events above a moderate size, but performs
well in predicting large events.Comment: 4 pages, 2 figures, Astronomical Society of Australia meeting in
Brisbane, July 2004; revised versio
Quality assurance in higher education - meta-evaluationof multi-stage evaluation procedures in Germany
Systematic procedures for quality assurance and improvement through evaluation have been in place in Western Europe since the mid 1980s and in Germany since the mid 1990s. As studies in Europe and beyond show that multi-stage evaluation procedures as the main quality assurance instrument for evaluation of teaching and learning in higher education institutions have proved reliable and have gained acceptance, in Germany (as well as in other countries) the evaluation of teaching and learning through internal and external evaluations has long come under the fire of criticism. Our results of the first comprehensive and representative investigation of procedures for the evaluation of teaching and learning in Germany show that former participants in the evaluations (reviewers and those reviewed) are satisfied all in all with the multi-stage procedure. They are convinced that the goals of quality assurance and improvement were achieved. Suggestions for improving the procedures target individual aspects, such as, for example, the composition of the review panel. Against this background, it makes sense to perform regular quality assessments of the procedures for quality assurance and improvemen
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