The principal of an elementary school wants to know how well her 600 students like the school. She hires a researcher, who gives a “satisfaction with school” survey to three different third-grade...

The principal of an elementary school wants to know how well her 600 students like the school. She hires a researcher, who gives a “satisfaction with school” survey to three different third-grade classes.

(a) How could the use of a sample like this threaten the value of the study’s outcomes??

(b) How might the flawed sample affect the usefulness of the results?