  The purpose of this study is to ascertain the suitability of GS's url-based
method as a valid approximation of universities' academic output measures,
taking into account three aspects (retroactive growth, correlation, and
coverage). To do this, a set of 100 Turkish universities were selected as a
case study. The productivity in Web of Science (WoS), Scopus and GS (2000 to
2013) were captured in two different measurement iterations (2014 and 2018). In
addition, a total of 18,174 documents published by a subset of 14
research-focused universities were retrieved from WoS, verifying their presence
in GS within the official university web domain. Findings suggest that the
retroactive growth in GS is unpredictable and dependent on each university,
making this parameter hard to evaluate at the institutional level. Otherwise,
the correlation of productivity between GS (url-based method) and WoS and
Scopus (selected sources) is moderately positive, even though it varies
depending on the university, the year of publication, and the year of
measurement. Finally, only 16% out of 18,174 articles analyzed were indexed in
the official university website, although up to 84% were indexed in other GS
sources. This work proves that the url-based method to calculate institutional
productivity in GS is not a good proxy for the total number of publications
indexed in WoS and Scopus, at least in the national context analyzed. However,
the main reason is not directly related to the operation of GS, but with a lack
of universities' commitment to open access.
