| Term | Definition |
| interest group | an organization of people with shared policy goals entering the policy process at several points to try to achieve those goals |
| pluralist theory | says politics is mainly a competition among groups, each one pressing for its own preferred policies |
| elite theory | says societies are divided along class lines and the upper class will rule, regardless of the formal niceties of governmental organization |
| hyperpluralist theory | says groups are so strong that government is weakened |
| subgovernments | a network of groups within the American political system that exercise a great deal of control over specific policy areas |
| potential group | all the people who might be interest group members because they share some common interest |
| actual group | the part of the potential group consisting of members who really join |
| collective good | something of value that cannot be withheld from a group member |
| free-rider problem | the problem faced by unions and other groups when people do not join because they can benefit from the group's activities without officially joining |
| Olson's law of large groups | "the larger the group, the further it will fall short of providing an optimal amount of collective good" |
| selective benefits | goods that a group can restrict to those who pay their annual dues |
| single-issue group | groups that have a narrow interest (tend to dislike compromise) |
| lobbying | "communication... directed to a governmental decision maker" |
| electioneering | direct group involvement in the electoral process |
| political action committees | political funding vehicles created by the 1974 campaign finance reforms |
| amicus curiae briefs | aim to raise additional points of view (submitted by a "friend of the court" in support of one side of a case) |
| class action lawsuits | lawsuits permitting a small number of people to sue on behalf of all other people similarly situated |
| union shop | a provision found in some collective bargaining agreements requiring all employees of a business to join the union |
| right-to-work laws | forbid requirements that workers must join a union to hold their jobs |
| public interest lobbies | organizations that seek "a collective good, the achievement of which will not selectively and materially benefit" people |