Cochrane Database of Systematic Reviews: Indexing, Citations & Bibliometrics
-
Upload
cochranecollaboration -
Category
Health & Medicine
-
view
5.948 -
download
0
description
Transcript of Cochrane Database of Systematic Reviews: Indexing, Citations & Bibliometrics
COCHRANE DATABASE OF SYSTEMATIC REVIEWS
INDEXING, CITATIONS & BIBLIOMETRICS
Adam FinchBibliometrics Analyst
Impact Factor: Meaning & Calculation
Impact Factor for JCR Year x = Citations in Year x to Papers from x-1 and x-2
Number of Source Items in x-1 and x-2
Cites in 2009 to articles published in:2008 = 2592 Number of articles published in: 2008 = 526 2007 = 3982 2007 = 637 Sum: 6574 Sum: 1163
Calculation: Cites to recent articles 6574 = 5.653Number of recent articles 1163
NB: Source Items are Articles, Reviews and Proceedings Papers; only these papers contribute to the denominator. Citations counted on the numerator, however, can be to any document type.
• Evaluates the impact of a journal based on a citation as a unit of quality • Based on ISI’s Web of Science and released in an annual Journal Citation Report• Essentially a measure of average citations per article
– Inconsistent standards for inclusion
Impact Factor: Strengths & Weaknesses
– Affected by ‘ citation inflation’
– Error correction difficult
– Subject area dependency
– Self-citation open to manipulation
+ Average cites-per-article makes sense
+ Comparatively easy to understand
+ Can be duplicated, predicted and simulated
+ Established and recognised metric
+ Broken down into ranked subject categories
2010 Impact Factor
2008 2009 ChangeImmediacy Index 1.131 1.311 15.9%Immediacy Index for Medicine, General & Internal 1.295 1.171 -9.6%
The Impact Factor will probably rise next year. 2010 IF looks at 2010 cites to 2009 and 2008 papers.
The Immediacy Index looks at citations in a given year to articles published in the same year.E.g. 2009 cites to 2009 papers ÷ # 2009 papers. A rise can indicate a strong year of papers.
Web of Science
Web of Science
Web of Science: Journal Data
• Bibliographic data (author, address, title, keywords, etc)
• Digital Object Identifier (DOI)
• Citation Report listing citations received each year since publication
• Client Article Reference (CD & Pub Numbers)
• Unique identifier for article with date of publication and page numbers
Web of Science: Cochrane Database of Systematic Reviews
• Bibliographic data (author, address, title, keywords, etc)
• Digital Object Identifier (DOI)
• Citation Report listing citations received each year since publication
• Client Article Reference (CD & Pub Numbers)
• Unique identifier for unique article with date of publication
Web of Science: Acquiring and Repairing the Data• Manually edit ISI article list of 2005—2008 papers so it matches actual content
• Match 15,000 citations to 2,431 target articles using:- Cited DOI Cited Article Reference Unique author in year
• Download all reviews in ISI subject category and process through in-house tools
• Search for and download all citations to CDSR for the past several years
• Add Review Group data from Editorial Office records
Author Document Type Region
Institution Country Review Group
Citation Incidence Citing Characteristics Top Cited Articles
• Analysis and reporting took days... Data acquisition and cleanup took weeks...
Analysis Highlights: CDSR
• Author loyalty. Of the 863 authors publishing reviews in CDSR that contributed to the 2009 Impact Factor, only 11 had more highly cited papers published elsewhere.
• Index comparison. Unfortunately, Elsevier’s Scopus does not provide a useful alternative data source.
The Scopus citation matching algorithm finds even fewer cites than WoS, despite looking at twice the number of citing journals.
Scopus contains a larger number of duplicate version entries due to the erroneous addition of variant Pubmed data to the records supplied by Wiley-Blackwell.
• Standard analyses less useful for CDSR.
Analysis Highlights: CDSR
Analysis Highlights: CDSR
Analysis Highlights: Subject Category