Paul N. Bennett Raman Chandrasekar Max Chickering Panagiotis G. Ipeirotis Edith Law Anton Mityagin Foster J. Provost Luis von Ahn Proceedings of the ACM SIGKDD Workshop on Human Computation, Paris, France, June 28, 2009 KDD Workshop on Human Computation ACM 978-1-60558-672-4 2009 db/conf/kdd/hcomp2009.html