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Bibliometrics: Journals, Articles, Authors
Thursday 11th February 2016.Tanya Williamson, Academic Liaison Librarian (Research)[email protected]
Overview
Learn about the most common bibliometrics, how to find them, the data they are based on, and their limitations.
1. What is citation analysis?2. Journal metrics 3. Author metrics4. Article level metrics and altmetrics
• Citation analysis is the quantitative analysis of research publications and citations
• Based on the assumption that citations = academic impact
• Bibliometrics are the measures produced by citation analysis
What is citation analysis?
Citation counts in Web of Science Graphic from Eigenfactor.org
Citation counts in Scopus
Article-level metrics in Scopus
SciVal and InCites are research intelligence tools based on citation data +
Key tools for finding bibliometric dataProduct Pros Cons
Web of Science(incl. Journal Citation Reports)
• Citation data back to 1945• Produces the Journal Impact Factor• Can compare journals within subject
category
• Less intuitive user interface• English language bias• Excludes some new OA journals• Journal Citation Reports does not include
journals which are solely concerned with Arts & Humanities
Scopus • Broader coverage than WoS• Produces IPP and SNIP• Source data for the REF and World
University Rankings• Can compare journals across subject
• Citation data back to 1996 (backfilling to 1972)
• Journal comparisons limited to 10 titles• No subject category rank• English language bias
Google Scholar
• Free and easy to use• Very broad coverage i.e. yields high results• Good coverage of grey literature and books
• No clear coverage policy• Author metrics rely on authors creating
profiles or using additional software e.g. Publish or Perish
• ‘Top journals’ by language and H-index
An attempt to compare the influence and impact of journal titles in a particular discipline based on citations received.
Can be useful to inform decisions on strategic publishing alongside judgements about reaching the best audience for the research.
Commonly used metrics • Journal Impact Factor available through Journal Citation Reports,
based on Web of Science data• SJR (SCImago Journal rank) based on Scopus data• SNIP (Source Normalised Impact per Paper) based on Scopus data
Journal metrics
Journal Citation Reports category rank
PSYCHOLOGY – EXPERIMENTAL category rank
PSYCHOLOGY – SOCIAL category rank
The Journal Impact Factor is the average number of times articles from the Journal published in the past two years have been cited in the JCR year. Also available: 5 year Journal Impact Factor
Journal Impact FactorAn example: Cognition
• Based on source data from Web Of Science
• “The theory behind the eigenfactor metrics is that a single citation from a high-quality journal may hold more value than multiple citations from more peripheral publications.”
Eigenfactor and Article InfluenceAn example: Cognition
Demo of Journal Citation Reports
• Source Normalised Impact per Paper (SNIP)– enables comparison between disciplines with different citation conventions
• Impact Per Paper – same method as the JIF with different source data, and based on 3 years of citations
Scopus - SNIP and IPP
SCImago journal rankAn example: Developmental and Educational Psychology
• SCImago Journal Rank uses source data from Scopus• Based on the Google PageRank algorithm• Weights citations from high prestige journals and attempts
to balance the influence of the size of a journal
Developmental and Educational Psychology category rank
• Journal Impact Factor doesn’t work (at all/well) for every discipline due to different publishing patterns and coverage of different publication types
• Journal Impact Factor mustn’t be used to compare different disciplines
• Focusing only on journal metrics could lead to you overlooking smaller, specialist or emerging publications
• Dependent on the coverage and biases of the source data i.e. will include only citations from other items in the database
• The overuse of the JIF has encouraged gaming and false precision
• Can we infer individual impact from journal impact?
Limitations of journal metrics
Key metrics• Citation counts - uses a particular dataset to count how
many documents an author has had published, and how many citations those documents have received over time
• H-index, devised by: J. E. Hirsch in 2005
• There are several ‘improvements’ on the h-index, e.g. the g-index, the hc-index, the hIindex, the ACW index but none has gained the same popularity as the h-index
Author metrics
Easy explanation:If a scholar has 20 articles which have each been cited 20 times, s/he has an h-index of 20
Author metrics fromWeb of Science
Demo of Web of Science
Author metrics from Scopus
Demo of Scopus
Google Scholar • A way to find your own h-
index• The author needs to have a
Google Scholar profile
Author metrics from Google Scholar
Publish or Perish• Uses Google Scholar data• Many nuanced author
metrics• Needs careful checking of
results for duplicates and false results
Demo of Google Scholar
• Name ambiguity – getting a comprehensive, accurate list is not easy, even in Web of Science
• No one metric can capture all citations or ‘impacts’• May not be enough publications to be valid• Early career researchers will be at a disadvantage• Results will vary based on the source data• Citations ≠ endorsements of quality!
Limitations of author metrics
Resistance against the h-index, ImpactStory
• Citation data in Web of Science, Scholar, Google Scholar• Publishers’ interfaces often include citing articles
Metrics• Total cites• Cites per year• Average cites per paper, or per year• Field Weighted Citation Impact• Benchmark percentile (based on age of paper and subject area)• Usage: downloads and views• Emerging ‘altmetrics’
Article level metrics
Article level metrics
Article level metrics
Article level metrics
Article level metrics
“Article-Level Metrics (ALMs) leverage the acceleration of research communication made possible by the networked landscape of researcher tools and services. Also by incorporating the manifold ways in which research is disseminated, these article impact indicators are made available rapidly after publication and are continually updated.”
PLOS One Article Level Metrics Information
Frontiers: Article level metrics for an OA article published in Frontiers in Psychology
Article level metrics
Alternative metrics or altmetrics
ImpactStory: like a living publications CV. Adding metrics all the time https://impactstory.org/metrics
• Emerging alternative metrics which capture the attention that articles/works receive online
• Shows the broader, societal attention which may or may not translate into citations
Loop: metrics presented on an author’s profile
Altmetrics
Altmetric.com: watch social media sites, newspapers, government policy documents and other sources for mentions of scholarly articles to compile article level metrics.
Example: A highly cited clinical article from 1995?
Limitations of article level and altmetrics
Source of data Citations to article
Web of Science 2214
Google Scholar 3184
Scopus 2500
Publisher’s website 1626
Example:Martinez, F. D., Wright, A. L., Taussig, L. M., Holberg, C. J., Halonen, M., & Morgan, W. J. (1995). Asthma and wheezing in the first six years of life. New England Journal of Medicine, 332(3), 133-138.
Citation data from 10/2/2016
• There are multiple sources of citation data to consider• No single source is perfect, all have different coverage• Citation counts/metrics alone only tell part of the story• Publishing and citing patterns are different in different
disciplines (and even within disciplines like Psychology)• ‘Outputs’ other than journal articles and conference
proceedings may not be well-represented• Altmetrics give a view of the online attention surrounding
a work
Summary
• Journal metrics (Elsevier) • The State of Journal Evaluation (Thomson Reuters)• Publish or Perish (Harzing)• Measure Your Research Impact toolkit (Irish academic libraries)• Leiden manifesto as published in Hicks, Diana, et al. "The Leiden
Manifesto for research metrics." Nature 520 (2015): 429-431. • PlumX from Plum Analytics: another altmetrics tool not discussed in
this presentation
The University has a current subscription to SciVal and InCites, which are research intelligence tools which include benchmarking
based on citation data from Scopus and WoS respectively.
Follow up resources
