Five Ws, one H and many tweets

Widespread using of microblogs leads to have tremendous user generated data available which may characterize the social behavior and relationship of users. Beside the chance to extract some valuable information from the huge amount of data, there are a lot of non-trivial, task specific issue have to be solved to get real value. Detecting and characterizing events, defining users and their relationships, concluding on the reasons are all important questions, have to be understood well, to get a clear picture on the social network behavior of users and to answer WHO, WHEN, WHERE, WHAT, WHY and HOW questions.