Chapter 1, Problem 33SE

For Exercises 1.39 through 1.44, indicate whether the study is an observational study or a controlled experiment.

A researcher is interested in the effect of music on memory. She randomly divides a group of students into three groups: those who will listen to quiet music, those who will listen to loud music, and those who will not listen to music. After the appropriate music is played (or not played), she gives all the students a memory test.