Published on in Vol 21 , No 5 (2019) :May

1 Teachers College, Columbia University, New York, NY, US
2 Social Computing Department, Qatar Computing Research Institute, Hamad Bin Khalifa University, Doha, QA
3 Microsoft Research, Redmond, WA, US
4 Microsoft Research, Herzeliya, IL
5 Faculty of Industrial Engineering and Management, Technion - Israel Institute of Technology, Haifa, IL
*all authors contributed equally