In this paper, we explore the for-fun model (Cooper et al., 2010;Law et al., 2007;Von Ahn & Dabbish, 2004;Von Ahn et al., 2006), in which data is a by-product of some gameplay, often referred to as "Games with a Purpose" (Von Ahn & Dabbish, 2008), which have been shown to be very successful in many domains.
with respect to generation of paraphrases or phrase equivalents, (Chen & Dolan, 2011) present their paraphrase collection using video annotations, focusing primarily on viability of establishing Mechanical Turk for providing paraphrases in a productive way.