Power
Emerson (1962) defined power as relational, situational, and at least potentially reciprocal (Scott p. 302). It is not the characteristic of an individual but a property of a social relation. The power of superordinates is based on their ability and willingness to sanction others and the value of the reward and punishments in the eyes of these other people. An individual's power is based on all the resources they can employ to help or hinder another in the attainment of desired goals (Scott p. 302).
Scott defines interpersonal power as "the potential for influence that is based on one person's ability and willingness to sanction another person by manipulating rewards and punishments important to the other person". (Scott p. 303).

Power in Informal Groups
Homans (1961) and Blau (1964) both examine how power emerges in small groups. Both see the emergence of power as "a product of unequal exchange relations that occur when some individuals become increasingly dependent on others for services required in reaching their objectives" (Scott p. 303). In informal groups power is based on the characteristics of the individuals.

Power in Formal Organizations
In formal groups power is in part determined by design as well as by personal characteristics and group dynamics. Hierarchy gives some people power over others.

Rational perspectives emphasize the hierarchical and formal power structures in organizations. Formal positions avoid the "tensions" of trying to find superior people for certain positions, and power is more easily transferred when people come and go.

Natural perspectives note that no organization ever succeeds in rationally distributing power among individuals. The individual characteristics often erode the formal system and largely determine the true emergent power structure. Sometimes resources are co-opted to build power (e.g. critical information).