Search Results
Abstract
It appears popular, particularly among science administrators, to use citations and various citation measures for ranking scientists, as if such exercises would reflect the scientific potential of the persons considered. In recent time the Hirsch index h in particular has obtained visibility in this respect in view of its simplicity. We consider a possible extension of the concept of selective citations, which in fact is innate to the h index, and propose a simple generalization, indices H and Q, which to a degree supplement the information accompanying the evaluation of h. The H index keeps record of the “history” of citations and the quotient Q = H/h is a measure for the quality of a scientist based on the history of his/her citations.
Absztrakt
Az elmúlt évtizedekben jelentősen megnövekedett a társszerzős és ezen belül is a sokszerzős cikkek aránya a tudományos publikációk között. A cikk ennek a jelenségnek az okaival és a tudománymetriai elemzéseket illető következményeivel foglalkozik. Kitér a publikációknak és az idézeteknek a társszerzők közötti szétosztásának lehetőségeire, valamint a h-index és az önidézettség értelmezésének problémáira társszerzős cikkek esetében. Orv. Hetil., 2016, 157(13), 512–516.
Abstract
In this paper, a new indicator called the performance index (p-index) is used to rank a 100 most prolific economists. The p-index strikes the best balance between activity (total citations C) and excellence (mean citation rate C/P). The surprise is that the h-index, which is now universally accepted almost as a canonical tool for research assessment of individuals, research faculties and institutions and even for comparing performance of journals and countries, is actually a poor indicator of performance.
Abstract
In recent issues of the ISSI Newsletter, Egghe [2006a] proposed the g-index and Kosmulski [2006] the h(2)-index, both claimed to be improvements on the original h-index proposed by Hirsch [2005]. The aim of this paper is to investigate the inter-relationships between these measures and also their time dependence using the stochastic publication/citation model proposed by Burrell [1992, 2007a]. We also make some tentative suggestions regarding the relative merits of these three proposed measures.
Abstract
We present an application of the h-index in a context which does not include publications or citations. Rankings of library classification categories using the h-, g-and R-index are shown to be statistically equivalent. Moreover these indices seem to have the same discriminating power, as measured by the Gini concentration index. We further present best fitting Zipf-Mandelbrot functions for the h-distributions of classifications in different libraries.
Abstract
For determining the eminence of scientific journals, a new indicator stressing the importance of papers in the “elite set” (i.e., highly cited papers) is suggested. The number of papers in the elite set (P πv) is calculated with the equation: (10 log P) − 10, where P is the total number of papers in the set. The one-hundredth of citations (C) obtained by P πv papers is regarded as the πv-index which is field and time dependent. The πv-index is closely correlated with the citedness (C/P) of P πv papers, and it is also correlated with the Hirsch-index. Three types of Hirsch-sets are distinguished, depending on the relation of the number of citations received by the Hirsch-paper (ranked as h) and the paper next in rank (h + 1) by citation. The h-index of an Anomalous Hirsch-set (AH) may be increased by a single citation to a paper outside the Hirsch-core. (A set of papers may be regarded as AH, where the number of citations to the Hirsch-paper is higher than the h-index and the next paper in rank shows as many citations as the value of the h-index.)
Abstract
Two types of series of h-indices for journals published in the field of Horticulture during the period 1998–2007 are calculated.
Type I h-indices are based on yearly data, while type II h-indices use cumulative data. These h-indices are also considered
in a form normalised with respect to the number of published articles.
It is observed that type I h-indices, normalised or not, decrease linearly over a period of ten years. The type II series,
however, is not linear in nature: it exhibits partly a concave shape. This proves that the journals (in Horticulture) do not
exhibit a linear increase in h-index as argued by Hirsch in the case of life-time achievements of scientists.
In the second part of the paper, an attempt is made to study the relative visibility of a journal and its change over time,
based on h-indices of journals. It is shown that:
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the h-index over the complete period 1998–2007 of the journal Theoretical & Applied Genetics (h = 62) is much higher than that of all other journals in the field
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the relation between the number of publications and the type II h-index for the whole period is not an exact power law (as
it would have to be if the Egghe-Rousseau model were applicable)
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in order to study the dynamic aspects of journal visibility, a field-relative normalised h-ratio is defined to monitor systematic
changes in the field of Horticulture. Except for two journals, the Pearson correlation coefficient for yearly values of this
field-relative normalised h-ratio indicates that there is no systematic change of the performance of the journals with respect
to the field as a whole.
Abstract
Hirsch’s concept of h-index was used to define a similarity measure for journals. The h-similarity is easy to calculate from the publicly available data of the Journal Citation Reports, and allows for plausible interpretation. On the basis of h-similarity, a relative eminence indicator of journals was determined: the ratio of the JCR impact factor to the weighted average of that of similar journals. This standardization allows journals from disciplines with lower average citation level (mathematics, engineering, etc.) to get into the top lists.
Abstract
An indicator called the performance index (p-index) which can effectively combine size and quality of scientific papers, mocking what the h-index could do, emerges from an energy like term E = iC, where i is a measure of quality, expressed as the ratio of citations C to papers published P. In this paper, we demonstrate how this energy paradigm can be used for bibliometric research assessment. The energy assessment technique is demonstrated by applying it to the research assessment of all the countries listed in Essential Science Indicators. Partitioning is easily done by using contour lines on the two-dimensional iCE (impact–Citations–Energy) map.
Abstract
We investigate possible effects from a strong encouragement for a large number of publications on the scientific production of a Brazilian cell biology department. An average increase in individual absolute production and a concomitant decrease in individual participation in each paper were detected by traditional bibliometric parameters, such as number of publications, citations, impact factors and h index, combined to their “effective” versions, in which co-authorship is taken into consideration. The observed situation, which might well represent a national trend, should be considered as a strong warning against current criteria of scientific evaluation heavily based on uncritical counting of publications.
