Related Experiment Video
Updated: Jul 10, 2026

Comparing Bibliometric Analysis Using PubMed, Scopus, and Web of Science Databases
Published on: October 24, 2019
Calculating impact factor: how bibliographical classification of journal items affects the impact factor of large and
Rajna Golubic1, Mihael Rudes, Natasa Kovacic
1Department of Occupational Medicine, Andrija Stampar School of Public Health, Zagreb University School of Medicine, Zagreb, Croatia.
Abstract:
As bibliographical classification of published journal items affects the denominator in this equation, we investigated how the numerator and denominator of the impact factor (IF) equation were generated for representative journals in two categories of the Journal Citation Reports (JCR). We performed a full text search of the 1st-ranked journal in 2004 JCR category "Medicine, General and Internal" (New England Journal of Medicine, NEJM, IF = 38.570) and 61st-ranked journal (Croatian Medical Journal, CMJ, IF = 0.690), 1st-ranked journal in category "Multidisciplinary Sciences" (Nature, IF = 32.182) and journal with a relative rank of CMJ (Anais da Academia Brasileira de Ciencias, AABC, IF = 0.435). Large journals published more items categorized by Web of Science (WoS) as non-research items (editorial material, letters, news, book reviews, bibliographical items, or corrections): 63% out of total 5,193 items in Nature and 81% out of 3,540 items in NEJM, compared with 31% out of 283 items in CMJ and only 2 (2%) out of 126 items in AABC. Some items classified by WoS as non-original contained original research data (9.5% in Nature, 7.2% in NEJM, 13.7% in CMJ and none in AABC). These items received a significant number of citations: 6.9% of total citations in Nature, 14.7% in NEJM and 18.5% in CMJ. IF decreased for all journals when only items presenting original research and citations to them were used for IF calculation. Regardless of the journal's size or discipline, publication of non-original research and its classification by the bibliographical database have an effect on both numerator and denominator of the IF equation.
Related Concept Videos
Types of Impact
The coefficient of restitution is a metric for understanding the dynamics of impacts. It quantifies the ratio of relative velocity...
Impact Loading
In cases of elastic deformation,...
Sample Size Calculation
The sample size for the given experiment or sampling effort is fundamental to any study design. Sample size decides the number of...
Factors Affecting Activity Coefficient
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the...
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
Impact
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...