General knowledge offered by non-expert users is less carefully formulated than encyclopedia entries or lexicon word sense glosses

The crowdsourcing approach to the acquisition of general knowledge consists of soliciting verbally expressed information, or annotations of such information, from large numbers of web users, sometimes using either small financial rewards or the challenge of participating in simple games as inducements (Havasi et al. 2007; von Ahn 2006). Crowdsourcing has proved quite reliable for simple annotation/classification tasks (e.g., Snow et al. 2008; Hoffmann et al. 2009). However, general knowledge of