Temporary groups pass through a unique sequencing of actions called the punctuated-equilibrium model. At the first meeting, the group’s general purpose and direction is established and then a framework of behavioral patterns and assumptions through which the group will approach its project emerges, sometimes in the first few seconds. Once set, the group’s direction is unlikely to be reexamined throughout the first half of its life. This is a period of inertia—the group tends to become locked into a fixed course of action, even if it gains new insights that challenge initial patterns.

One of the most interesting discoveries in studies was that groups experienced a transition precisely halfway between the first meeting and the official deadline—whether members spent an hour on their project or 6 months. The midpoint appears to work like an alarm clock, heightening members’ awareness that they need to get moving. The transition sets a revised direction for phase 2, in which the group executes plans created during the transition.

The group’s last meeting is characterized by a final burst of activity to finish its work. This is not the only model of group stages, but it is a dominant theory with strong support. This model doesn’t apply to all groups but is suited to the finite quality of temporary task groups.