If you'd like to try this surveygizmo out for yourself, go to Questia and try to win an 80GB iPod by taking their survey. It's actually fun to complete, and the mechanism couldn't be smoother, or less aggravating.
A. Brew, D. Greene, и P. Cunningham. Proceedings of the 19th European Conference on Artificial Intelligence, том 215 из Frontiers in Artificial Intelligence and Applications, стр. 145--150. Amsterdam, The Netherlands, The Netherlands, IOS Press, (2010)