A probability sampling technique in which a researcher begins by identifying subgroups and then randomly samples from each groups is called probability sampling

The main reason we must be concerned with the perceptions of different countries is

a. that the world is a hostile place, and each country must be prepared for the worst. b. that some countries have the wrong perception of events, and it is important to know that before something dangerous happens. c. that perception is inherently related to policy choice. d. in fact, it is not all that critical that we understand different perceptions because countries usually choose similar policies anyway.

Provide an example of a source published annually that provides information about the United States

a) Wikipedia b) Annual Review c) The Statistical Abstract of the United States d) The New York Times Index