Hazing within college fraternities is a continuing concern to higher education officials. Prior to a national meeting of college presidents, a polling organization is retained to conduct a survey among fraternities on college campuses to gather information on hazing for use at the presidents' meeting.
The investigators from the polling organization realize that it is not possible to find a reliable sampling frame of all fraternities. Using a list of all college institutions, the investigators randomly select 30 college institutions, and then interview the officers of every fraternity at each of these 30 institutions.
Question 1. Is this a simple random sample, cluster random sample, or stratified random sample?