The California State University $($CSU$)$ system consists of $23$ campuses, from San Diego State in the south to Humboldt State near the Oregon border. A CSU administrator wishes to make an inference about the average distance between the hometowns of students and their campuses. Describe and discuss several different sampling methods that might be employed. $($Select all that apply.$)$

Certain problems arise with self reporting of distances, such as recording error or poor recall.