1. naturally occurring patterns of growth and change that unfold across the lifespan of a group. The term usually implies a progressive movement toward a more complete or advanced state, with different theorists characterizing this movement (a) as either discontinuous and occurring in distinct stages or continuous and incremental and (b) as either irreversible or cyclical and repetitious. See also equilibrium model of group development.

2. a strategic intervention designed to alter the processing and functioning of a group; this usually involves assessing the group’s current level of development, helping to clarify its mission and goals, and reviewing its operating procedures. See also team building.