Google Scholar as a cybermetric tool Alastair G Smith Victoria University of Wellington New Zealand

Overview Google Scholar as a cybermetric tool Used to compare web citation rates with results of a research assessment exercise: New Zealand’s Performance Based Research Fund (PBRF).

Cybermetrics Quantitative analysis of published research on the Internet Emulates techniques used by bibliometrics in the conventional publishing environment

Tools for cybermetric work General purpose search engines, e.g. Alta Vista Google Specialised cybermetric crawler, e.g. Wolverhampton Academic Web Link Database (

General purpose search engines Search algorithms not transparent Priority is to provide satisfactory search, not exact result Cover all of web, not just research material

Specialised cybermetric crawler Search algorithm publicly documented Oriented to cybermetric purposes Focussed on specific research institutions

Google Scholar Indexes research oriented material on the Internet (though selection criteria not published) Includes citation information Citations include print material referenced in Internet documents Potential as cybermetric tool?

PBRF research assessment Research assessment exercise: NZ Tertiary institutions 2003/4 Assessed research outputs from staff Institution ratings include: Total output Quality score: average output per staff member Ratings determine grants from Performance Based Research Fund Benchmark to compare with cybermetric study?

Specialised crawler study Previous study (Smith & Thelwall 2005) Compared links to NZ university web sites with PBRF rankings. Moderate correlation: Link count/staff cf PBRF quality score Issues: NZ-NZ links, ignores international linkage Includes non-research material

Google Scholar study Searched Google Scholar for research originating from the 8 NZ universities Citation counts for this material extracted Compared with PBRF ratings

Methodology issues with Google Scholar Problems identifying output of institution No total citation count provided

Identifying institution No “institution” field Domain name search produces false drops (e.g. mirrored research ), misses research hosted at other institutions (e.g. paper presented at external conference) Searched on words in name of institution, and location e.g. "canterbury university" OR "university of canterbury" zealand OR christchurch OR ilam

Google Scholar result screen

Obtaining citation count Total citation count not displayed Only first 1000 hits obtainable (but citation counts appear to be used in ranking) Extracted individual citation counts with macro Assumed citation counts for first 1000 hits a good approximation for total citation count.

Results: Citations vs PBRF output

Results: Hits vs PBRF output

Comparison of cybermetric tools CoverageIdentification of institutions Citation count Transparency Google ScholarResearch on Web By keywordIndividual, cannot display all hits Little documentation of algorithm, selection of sources Web of Knowledge Core journals (some digital) Specific fieldFor individual items Sources documented Scopus Core journals + Web sites (from Scirus) Specific field“Citation tracker” only for authors Sources documented Wolverhampton Crawler Specific university web sites By domainLink counts Sources documented

Pros and Cons of using Google Scholar for cybermetrics Pros: Good coverage of research on Web Accessible and simple Cons Not transparent Need to use ad hoc search for institution

Institutional repositories Could provide good target for specialised cybermetric crawler, if: Standardised formats for citations etc Standard selection criteria Accessible to crawlers

Summary Google Scholar provides a useful tool for “quick and dirty” cybermetric work Results have some correlation with a general research assessment Institutional repositories may provide a useful way of evaluating institutions