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