Question

A researcher has decided to do a study with people who have adopted children from outside the United States. He talks with a friend, whom he knows recently adopted, and asks if he would consent to an interview. He interviews his friend, and then asks his friend if he could give his contact information to other people who have recently adopted children from outside of the United States. His friend shares the researcher's contact information with five friends. The researcher eventually interviews those five people and asks them to share his contact information with any adoptive families in their friendship networks. This sampling technique is known as:

Answer 1

The sampling technique used in this case is a probability sampling because the researcher selects a random members of a population by setting a few selection criteria, in this case, people who have adopted children from outside the United States. These selection "rules" or parameters allow every member to have the equal opportunities to be a part of various samples as it seems to be the objective of the researcher because he asked them to exchange their contact information.