Suppose the university wants to find out from the whole student body whether they support adding a swimming pool to the recreation center. Name the type of sampling for each item and discuss each in terms of bias (say more than "biased" or "not biased").
A) A notice in the student newspaper invites all students to email their opinions.
B) Telephone at random 20 groups of five names in an alphabetical list of the student body.

Question

Quizplus · Accepted Answer

The Answer is A) This is a self-selected (or voluntary) sample because only those interested enough to respond will be represented. This sample could represent a bias because those interested in swimming would be more likely to respond.
B) This is a cluster sample. Although there may be no bias in how the names are distributed in the telephone book, it is possible that those students without telephones might have different opinions. If there are a lot of students without telephones, the sample could be biased.

Suppose the University Wants to Find Out from the Whole