Polling universe
From dKosopedia
Polling universe
A polling universe is the set of people that a particular poll is meant to represent. For American political polls, the ideal universe is the collection of people in the United States who will cast a vote is the next election. Most polling firms try to capture this elusive group by creating samples for lists of registered voters or the vaguely named and never adequately defined "likely voters". Other polling firms attempt instead to create a sample that captures the views of the entire adult American population. The choice of universe and the construction of a sample based on the target universe is a large component of the methodology of the poll.