Open access and sources of full-text articles in Google Scholar in different subject fields

Jamali, H. R., Nabavi, M. 
Open access and sources of full-text articles in Google Scholar in different subject fields. 
Scientometrics, (Online Version: 23 july 2015) 

DOI 10.1007/s11192-015-1642-2

Objectives
1. To determine the rate of full-text availability of items in GS according to disciplines.
2. To identify the sources of bibliographic information and full-text files in GS.
3. To determine any possible correlation between full-text availability, number of versions and number of citations.
Methods
Three queries were created for each of 277 minor subject categories of Scopus. The queries were searched in Google Scholar and the first ten hits for each query were analyzed.  8310 items were analyzed. Citations and patents were excluded from the results and the time frame was limited to 2004–2014.
Results
- 61.1 % of articles were accessible in full-text in Google Scholar; 
- 80.8 % of full-text articles were publisher versions
- 69.2 % of full-text articles were PDF. 
- There was a significant difference between the means of times cited of full text items and non-full-text items. 
- The highest rate of full text availability for articles belonged to life science (66.9 %). 
- Publishers’ websites were the main source of bibliographic information for non-full-text articles. 
- For full-text articles, educational (edu, ac.xx etc.) and org domains were top two sources of full text files. 
- ResearchGate was the top single website providing full-text files (10.5 % of full-text articles).

Available in

http://link.springer.com/article/10.1007/s11192-015-1642-2