Bibliometrics

Dan Holden

Limitations Assessment of research impact

◦ Calculating h-index using Web of Science and

Publish or Perish Assessment of journal quality

◦ Calculating Impact Factor using Journal Citation

Reports

◦ Calculating h-index using Publish or Perish

◦ Other metrics and tools

Major Metrics and Key Tools

Metrics and tools not well established for arts, humanities and social sciences

Citation patterns vary from subject to subject Coverage of tools is not comprehensive Self-citations can distort metrics Review articles are more highly cited than

standard articles Citations to a paper may not reflect its quality Metrics tend not to account for age of researcher

Limitations

Publication count

◦ Number of publications produced by individual,

school or university

Citation count

◦ Number of times publication is cited by other

publications

Major Metrics: Research Impact

h-index

◦ Defined as largest number h, where a

researcher has at least h publications cited at

least h times

◦ Eg an h-index of 25 tells us that an author has

written 25 papers which have each been cited

at least 25 times

Major Metrics: Research Impact

Web of Science◦ Covers over 11,500 journal titles and 120,000

conference proceedings◦ Consists of:

Science Citation Index - 1970 to present Social Sciences Citation Index - 1970 to

present Arts & Humanities Citation Index - 1975 to

present◦ Limited coverage of non-English language titles◦ Does not include books, book chapters or

theses

Key Tools: Research Impact

SCOPUS◦ Covers over 18,000 journal titles and 4.4 million

conference papers◦ Better coverage of social science titles than

Web of Science ◦ Better coverage of non-English language

publications from Europe than Web of Science ◦ Citation data only available for papers

published from 1996 onwards◦ Does not include books, book chapters or

theses

Key Tools: Research Impact

Publish or Perish

◦ Free analysis tool used in conjunction with

Google Scholar

◦ Google Scholar covers much wider range of

material than Web of Science or Scopus

◦ Better coverage of non-English language

publications from Africa, Asia and Central and

South America than Web of Science or Scopus

◦ No source list or indication of timescale covered

Key Tools: Research Impact

Journal Impact Factor (JIF)

◦ Average number of times articles published in

journal in past 2 years have been cited in

current year

◦ Eg title with JIF of 1 in 2010 means that articles

published in 2008 or 2009 have been cited on

average once in 2010

Major Metrics: Journal Quality

h-index

◦ Increasingly applied to journals

◦ Largest number h, where a journal has at least

h of its articles cited at least h times

◦ Eg journal has an h-index of 10 if 10 of its

papers have each been cited at least 10 times

Major Metrics: Journal Quality

Journal Citation Reports

◦ Produced using data from Science Citation

Index and Social Sciences Citation Index

◦ Covers over 10,500 journals

◦ Reports from 2000 to 2010 are available

Publish or Perish

Key Tools: Journal Quality

SCImago Journal & Country Rank

◦ Free service

◦ Based on SCOPUS data

◦ Key metric is SCImago Journal Rank (SJR)

indicator – underlying number of citations

received by number of articles published

calculation but citations are weighted

depending on ‘prestige’ and subject area

Other Metrics and Tools: Journal Quality

Source-Normalized Impact per Paper (SNIP)◦ Free service◦ Based on SCOPUS data◦ Underlying citations received by number of

articles published calculation but divided by Citation Potential of subject area

◦ Citation Potential is likelihood of being cited in particular subject area

◦ SJR and SNIP are components of Journals Analyzer tool in SCOPUS

Other Metrics and Tools: Journal Quality

Eigenfactor

◦ Free service

◦ Eigenfactor Score (EFS) is like SJR but uses Web of Science data, self-citations are not included and citations are counted over 5 years rather than 3 years

◦ Article Influence Score (AIS) is average influence of journal's articles. Calculated by dividing EFS by number of articles in journal (mathematically adjusted so it is comparable with other journals)

Other Metrics and Tools: Journal Quality

Eigenfactor www.eigenfactor.org Library’s A to Z list of databases (via QSearch)

metalib.qub.ac.uk Library’s Bibliometrics pages: go.qub.ac.uk/ygaab Measuring Your Research Impact www.ndlr.ie/myri SCImago Journal & Country Rank

www.scimagojr.com/ SCOPUS www.scopus.com Source-Normalized Impact per Paper (SNIP)

www.journalmetrics.com/

Useful Links