  Funding acknowledgements found in scientific publications have been used to
study the impact of funding on research since the 1970s. However, no broad
scale indexation of that paratextual element was done until 2008, when Thomson
Reuters Web of Science started to add funding acknowledgement information to
its bibliographic records. As this new information provides a new dimension to
bibliometric data that can be systematically exploited, it is important to
understand the characteristics of these data and the underlying implications
for their use. This paper analyses the presence and distribution of funding
acknowledgement data covered in Web of Science. Our results show that prior to
2009 funding acknowledgements coverage is extremely low and therefore not
reliable. Since 2008, funding information has been collected mainly for
publications indexed in the Science Citation Index Expanded (SCIE); more
recently (2015), inclusion of funding texts for publications indexed in the
Social Science Citation Index (SSCI) has been implemented. Arts & Humanities
Citation Index (AHCI) content is not indexed for funding acknowledgement data.
Moreover, English-language publications are the most reliably covered. Finally,
not all types of documents are equally covered for funding information
indexation and only articles and reviews show consistent coverage. The
characterization of the funding acknowledgement information collected by
Thomson Reuters can therefore help understand the possibilities offered by the
data but also their limitations.
