Ashikawa, Masayuki, Takahiro Kawamura, and Akihiko Ohsuga. 2015. “Proposal of Grade Training Method in Private Crowdsourcing System”. Proceedings of the AAAI Conference on Human Computation and Crowdsourcing 3 (1):2-3. https://doi.org/10.1609/hcomp.v3i1.13246.