Social network Extensively studied by social scientists for decades. Usually small datasets. Social networks on Internet are gigantic Facebook,Twitter,Linkedln,WeChat,Weibo,.. A large class of tasks/studies are about the influence and information propagation. A typical task:select some seed customers and let them influence others. 3Social network ◼ Extensively studied by social scientists for decades. ❑ Usually small datasets. ◼ Social networks on Internet are gigantic ❑ Facebook, Twitter, LinkedIn, WeChat, Weibo, … ◼ A large class of tasks/studies are about the influence and information propagation. ◼ A typical task: select some seed customers and let them influence others. 3