From Beatson, Buettner, & Schirato, 2014:
Estellés and González (2012, 9) define crowdsourcing as ‘a type of participative online activity in which an individual, an institution, a non-­profit organisation, or company proposes to a group of individuals of varying knowledge, heterogeneity, and number, via a flexible open call, the voluntary Undertaking of a task’.