Question

Eating on campus The director of student life at a small college wants to know what percent of students eat regularly in the cafeteria. To find out, the director selects an SRS of 300 students who live in the dorms. Describe how undercoverage might lead to bias in this study. Explain the likely direction of the bias.

Answer 1

Answer:

Well, in this case all the students selected live in the dorms, so it is actually likely that they eat in the cafeteria regularly.

For example, a student that lives in a house (with family, friends, etc) may have access to eat in his own place or may have larger economic freedom, so maybe they go and eat out. In this group, you may find that the probability for a randomly selected student eats in the cafeteria regularly may be smaller than in the group of the students that live in the dorms.

So the sample will be biassed towards eating regularly in the cafeteria.