[IEEE 2012 IEEE Second International Conference on Healthcare Informatics, Imaging and Systems Biology (HISB) - La Jolla, CA, USA (2012.09.27-2012.09.28)] 2012 IEEE Second International Conference on Healthcare Informatics, Imaging and Systems Biology - Cheap, Fast, and Good Enough for the Non-biomedical Domain but is It Usable for Clinical Natural Language Processing? Evaluating Crowdsourcing for Clinical Trial Announcement Named Entity Annotations