WeChat data Group: groups generated on July 26th, 2015 User: group members users in fringe Inv itation: u, v, C, T) Friendship: u, V, T) Category Type Number Group Total 474.726 Member Grou Min group size M ax group size 500 Fringe User nvitation T0201357 friendi Friendship Total624,529,005
6 WeChat Data Fringe Group Member • Group: groups generated on July 26th, 2015 • User: group members + users in fringe • Invitation: (u, v, C, T) • Friendship: (u, v, T) Invite friend
Group Lifecycle Dichotomy Definition Gro a group is initial sends chat How long would a group chat survive? 10 0.4 0.2 10 00L 51015202530 Group Lifespan(day) Group Lifespan(day) Short-term group vs Long-term group
7 Group Lifecycle Dichotomy Definition: Group Lifespan. Duration from the timestamp at which a group is initialized, to the timestamp at which no group members sends chat messages anymore. Short-term group v.s Long-term group How long would a group chat survive?
Group Lifecycle Dichotomy Case Stud Table 2: Case study by group displayed name. Category Long Short Example Travel Discuss on a short trip Meeting 2 Schedule an official meeting Event Entertain 01459 13 Plan a wedding 13 Dine together Organization 0 Departments of company Cla 12 Course for gre Friend 13 0 Childhood friend Family 16 0 A family of three Short-term group v s Long-term group Event-driven v.S. Relationship-driven
8 Group Lifecycle Dichotomy – Case Study Short-term group v.s Long-term group Event-driven v.s. Relationship-driven
Group Lifecycle Dichotomy -Structure Dynamics Open Triad 10 losed jad Long-term · Long-tem Short-term · Short-term 10 10 10 #Open triad( setting up) #Closed triad( setting up) (a) Example (b)Open triads (c)Closed triads Long-term Group: Strong dynamics in terms of underlying friendship structure Short-term Group: Less likely to develop friendship over time
9 Group Lifecycle Dichotomy – Structure Dynamics Open Triad Closed Triad • Long-term Group: Strong dynamics in terms of underlying friendship structure. • Short-term Group: Less likely to develop friendship over time
Group Lifecycle Dichotomy -Group Cascade Tree Definition: Group Cascade Tree. a directed graph where each group member is a node, and a directed edge from u to v is constructed if u(inviter) successfully invites v(invitee) to the group Example of long-term grou WeChat Group Group Cascade Tree →自中 5。 Example of short-term gro
10 Group Lifecycle Dichotomy – Group Cascade Tree Definition: Group Cascade Tree. A directed graph where each group member is a node, and a directed edge from u to v is constructed if u (inviter) successfully invites v (invitee) to the group. Invite Group Cascade Tree Invite WeChat Group Example of long-term groups Example of short-term groups