Research Metrics

Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines. Released in November 2004, the Google Scholar index includes peer-reviewed online journals of Europe and America's largest scholarly publishers, plus scholarly books and other non-peer reviewed journals. While Google does not publish the size of Google Scholar's database, third-party researchers estimated it to contain roughly 160 million documents as of May 2014 and an earlier statistical estimate published in PLOS ONE estimated approximately 80-90% coverage of all articles published in English.  Description text available under the Creative Commons Attribution-ShareAlike License.

 

The service indexes across a wide range of sources from academic disciplines including academic publishers, professional societies, online repositories, universities and other academic websites. As a consequence, citation counts in Google Scholar can often be much higher than other subscription-based citation indexing services.

A paper is ranked in part by how often and how recently it has been cited in other scholarly works also indexed by Google. Search results for individual papers include a total citation count with a link to view a list of all other citing papers.

Google Scholar Citations lets authors track citations to their own publications over time.