Google Scholar

Publish or Perish uses Google Scholar as one of its data sources. This means that any advantages and disadvantages that are present in Google Scholar will also be present in Publish or Perish. As an alternative you can also use Microsoft Academic in Publish or Perish. If you prefer to work with ISI/Web of Science data or Scopus data, you can use ISI Import or Scopus Import

Google Scholar has come a long way...

Google Scholar has come a long way since the early days of its introduction in 2004. Its coverage has improved dramatically and is now better for all disciplines than either the Web of Science or Scopus. As a result there are now many bibliometric studies that rely on Google Scholar (with Publish or Perish) to do their research. An all of the words Google Scholar search for the words: Harzing "Publish or Perish" results in nearly 2,000 hits.

Google Scholar is not a bibliometric database

However, just like Publish or Perish, Google Scholar is free and does not charge any subscription fees. Its data rely on crawling websites with scholarly articles. Thus one cannot expect the same level of accuracy as manually curated databases such as the Web of Science and Scopus, that charge universities a very hefty subscription fee.

Sacrifice a little accuracy for a lot more comprehensive coverage

That said, based on my own and other recent research on Google Scholar I would estimate that - ignoring the [citation] records - its accuracy lies above 95%. Scopus and the Web of Science probably have an accuracy level of above 99%, but the comprehensiveness of their coverage is much lower than Google Scholar.

Google Scholar vs Web of Science and Scopus

The table below summarises part of the results of our recent study of 146 academics in the Life Sciences, Sciences, Engineering, Social Sciences and Humanities.

Discipline Scopus citations as % of
Google Scholar citations
Web of Science citations as % of
Google Scholar citations
Humanities 11.5% 7.0%
Social Sciences 30.0% 22.7%
Engineering 57.6% 45.7%
Sciences 64.2% 65.6%
Life Sciences 70.5% 66.8%

As is immediately apparent, both the Web of Science and Scopus miss a huge number of citations in the Humanities and Social Sciences, mostly because they do not include book publications and in some disciplines cover only a fraction of the journals. However, even in Engineering, the Sciences and the Life Sciences, Google Scholar reports between one-and-a-half and twice as many citations as the Web of Science and Scopus.

However, there are a number of "quirks"

Truncation Book edition cites
Wrong master record Missing subject areas
Wrong author(s) Citation years
Inconsisten year Slow searches
Stray citations CAPTCHAS

References

Support Publish or Perish

The development of the Publish or Perish software is a volunteering effort that has been ongoing since 2006. Download and use of Publish or Perish is and will remain free (gratis), but your support toward the costs of hosting, bandwidth, and software development are appreciated. Your support helps further development of Publish or Perish for new data sources and additional features.