Wren, JD (Wren, Jonathan D.) URL decay in MEDLINE - a 4-year follow-up study BIOINFORMATICS, 24 (11): 1381-1385 JUN 1 2008

[Eugene Garfield]

Email Address:   Jonathan.Wren at OU.edu

Author(s): Wren, JD (Wren, Jonathan D.) 

Title: URL decay in MEDLINE - a 4-year follow-up study 

Source: BIOINFORMATICS, 24 (11): 1381-1385 JUN 1 2008 

Language: English 

Document Type: Article 

Keywords Plus: INTERNET REFERENCES; WEB REFERENCES; ACCESSIBILITY; 
PERSISTENCE; INFORMATION; CITATIONS; JOURNALS; AVAILABILITY; PERMANENCE; 
STABILITY 

Abstract: Motivation: Internet-based electronic resources, as given by 
Uniform Resource Locators (URLs), are being increasingly used in 
scientific publications but are also becoming inaccessible in a time-
dependant manner, a phenomenon documented across disciplines. Initial 
reports brought attention to the problem, spawning methods of effectively 
preserving URL content while some journals adopted policies regarding URL 
publication and begun storing supplementary information on journal 
websites. Thus, a reexamination of URL growth and decay in the literature 
is merited to see if the problem has grown or been mitigated by any of 
these changes.
Results: After the 2003 study, three follow-up studies were conducted in 
2004, 2005 and 2007. Unfortunately, no significant change was found in the 
rate of URL decay among any of the studies. However, only 5 of URLs cited 
more than twice have decayed versus 20 of URLs cited once or twice. The 
most common types of lost content were computer programs (43), followed by 
scholarly content (38) and databases (19). Compared to URLs still 
available, no lost content type was significantly over- or 
underrepresented. Searching for 30 of these websites using Google, 11 (37) 
were found relocated to different URLs.
Conclusions: URL decay continues unabated, but URLs published by 
organizations tend to be more stable. Repeated citation of URLs suggests 
calculation of an electronic impact factor (eIF) would be an objective, 
quantitative way to measure the impact of Internet-based resources on 
scientific research. 

Addresses: Oklahoma Med Res Fdn, Arthritis & Immunol Res Program, Oklahoma 
City, OK 73104 USA 

Reprint Address: Wren, JD, Oklahoma Med Res Fdn, Arthritis & Immunol Res 
Program, 825 NE 13th St, Oklahoma City, OK 73104 USA. 

Cited Reference Count: 30 

Times Cited: 0 

Publisher: OXFORD UNIV PRESS 

Publisher Address: GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND 

ISSN: 1367-4803 

29-char Source Abbrev.: BIOINFORMATICS 

ISO Source Abbrev.: Bioinformatics 

Source Item Page Count: 5 

Subject Category: Biochemical Research Methods; Biotechnology & Applied 
Microbiology; Computer Science, Interdisciplinary Applications; 
Mathematical & Computational Biology; Statistics & Probability 

ISI Document Delivery No.: 305HQ 

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