Golubic, R; Rudes, M; Kovacic, N; Marusic, M; Marusic, A Calculating impact factor: How bibliographical classification of journal items affects the impact factor of large and small journals SCIENCE AND ENGINEERING ETHICS, 14 (1): 41-49 MAR 2008

[Eugene Garfield]

E-mail Address: ana.marusic at agram.mef.hr 

Author(s): Golubic, R (Golubic, Rajna); Rudes, M (Rudes, Mihael); Kovacic, 
N (Kovacic, Natasa); Marusic, M (Marusic, Matko); Marusic, A (Marusic, 
Ana) 

Title: Calculating impact factor: How bibliographical classification of 
journal items affects the impact factor of large and small journals 

Source: SCIENCE AND ENGINEERING ETHICS, 14 (1): 41-49 MAR 2008 

Language: English 

Document Type: Article 

Author Keywords: journal; impact factor; bibliographical database; 
indexing 

Keywords Plus: SCIENCE; QUALITY 

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. 

Addresses: Univ Zagreb, Sch Med, Andrija Stampar Sch Publ Hlth, Dept 
Occupat Med, Zagreb 10000, Croatia; Univ Zagreb, Ctr Hosp, Dept ENT, 
Zagreb, Croatia 

Reprint Address: Marusic, A, Univ Zagreb, Sch Med, Andrija Stampar Sch 
Publ Hlth, Dept Occupat Med, Salata 3, Zagreb 10000, Croatia. 

Cited Reference Count: 15 

Times Cited: 0 

Publisher: SPRINGER 

Publisher Address: VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS 

ISSN: 1353-3452 

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