Google Scholar, Scopus and Web of Science: effective, but how do they really work?

Article type
Authors
Kotas E1, Cooper C2
1Liverpool Reviews and Implementation Group, University of Liverpool
2Systematic Review Initiative, NHS Blood & Transplant, University of Oxford
Abstract
Background:
Various studies have analysed the effectiveness of leading citation databases for citation chasing in systematic reviews. The findings of these studies are mixed and current best practice suggests that it remains necessary to use a combination of Web of Science, Scopus and Google Scholar to ensure a comprehensive identification of studies when citation chasing in systematic reviews.
In this presentation, we look beyond effectiveness (i.e. do they work) to develop our understanding of how these citation databases work and we consider the impact of this understanding for researchers.

Methods:
We sought answers to the following three questions for Web of Science, SCOPUS and Google Scholar:

1) How are studies identified for inclusion in citation databases?
2) What is the timeframe for the identification and inclusion of studies?
3) How are studies 'indexed' into the respective databases?

We attempted to identify the answers through web searching and contacting the organisations that manage or promote the resources.

Results:
Our work is ongoing. The results will be reported in the oral presentation.

Conclusions:
Current best practice is to search Web of Science, Scopus and Google Scholar to ensure comprehensive identification of studies. This is costly and creates research waste. In this presentation we focus on how studies are identified, the timeframe for identification and inclusion, and how studies are 'indexed' in these resources. This will advance the science on resource selection.