Little has been written on the form that coalitions take in social movement
s. Three months of fieldwork by a five-person team documented the populatio
n of social movement events (SMEs) across seven movements in a Southwestern
city. We investigated the process and form that led to these events at the
interorganizational level. Three different coalition forms, as well as sin
gle social movement organizations (SMOs) acting alone, organized the SMEs.
The "network invocation" form-a single SMO making strategic and framing dec
isions while encouraging other SMOs in its network to mobilize participants
-was significantly more effective than other forms at mobilizing attendance
at events.