KDD Cup 2015 - Predicting dropouts in MOOC https://www.kddcup2015.com/information.html MOOCのコースからの脱落の予測という、なんという身近な問題…… 

Timeline:
May 1 - May 15: Review Problem and Download Data 
June 23: Team Merger Deadline 
June 29: First Submission Deadline 
July 5: End Date 
July 10: Winner Announcement