References made and citations received by scientific articles

Abstract

This article studies massive evidence about references made and citations received after a 5-year citation window by 3.7 million articles published in 1998 to 2002 in 22 scientific fields. We find that the distributions of references made and citations received share a number of basic features across sciences. Reference distributions are rather skewed to the right while citation distributions are even more highly skewed:The mean is about 20 percentage points to the right of the median, and articles with a remarkable or an outstanding number of citations represent about 9% of the total. Moreover, the existence of a power law representing the upper tail of citation distributions cannot be rejected in 17 fields whose articles represent 74.7% of the total. Contrary to the evidence in other contexts, the value of the scale parameter is above 3.5 in 13 of the 17 cases. Finally, power laws are typically small, but capture a considerable proportion of the total citations received.

Average-based versus high- and low-impact indicators for the evaluation of scientific distributions

“…1 See inter alia Seglen (1992), Shubert et al (1987) for evidence concerning scientific articles published in the period 1981-85 in 114 sub-fields, Glänzel (2007) for articles published in 1980 in 12 broad fields and 60 middlesized disciplines, Albarrán and Ruiz-Castillo (2009) for articles published in the period 1998-2002 in 22 broad fields, and Albarrán et al (2010a) for these same articles classified in 219 Web of Science categories and three aggregation schemes consisting of a number of disciplines and broad fields.…”

Posted, visited, exported: Altmetrics in the social tagging system BibSonomy

“…Since the threshold x min is very high -x min = 808 means that the part of the distribution that is fitted contains only publications with at least 808 citations -, we also consider the second (local) optimum: α = 2.34 for x min = 303. The exponents α of both fits are lower than reported by both Brzezinski (2015) and Albarrán & Ruiz-Castillo (2011). This is evidence that our corpus, which is collected from a web system, is indeed different to corpora that are collected from traditional article catalogs like Web of Science or Scopus.…”

“…To determine the optimal fit, we used the methodology by Clauset et al (2009), that was also used in previous studies of citation distributions (Albarrán & Ruiz-Castillo, 2011;Brzezinski, 2015). The optimal fit has parameters α = 2.59 and x min = 808.…”

Evaluating research institutions: the potential of the success-index

“…The estimation will therefore be less subject to fluctuations, especially in the case of relatively small samples of publications (Albarrán and Ruiz-Castillo 2011).…”