interest group
an organization of people sharing a common interest or goal that seeks to influence public policy
incentive
something of value one cannot get without joining an organization
solidary incentives
the social rewards (Sense of pleasure, status or companionship) that lead people to join political organizations
material incentives
money or things valued in monetary terms
purposive incentive
a benefit that comes from serving a cause or principle
ideological interest groups
political organizations that attract members by appealing to their political convictions or principles
public-interest lobby
a political organization whose goals will principally benefit nonmembers
social movement
a widely shared demand for change in some aspect of the social or political order.
political cue
a signal telling a legislature what values are at stake in a vote, and how that issue fits into his or her own political views on a party agenda
ratings
assessments of a representative's voting record on issues important to an interest group