A music professor offers his 40 students the option of coming to an additional rehearsal session the week before their juries (musical final exams.) In order to decide whether these extra sessions actually help students, he keeps track of who attends them and compares their jury scores to those of students who did not schedule extra sessions.
This study is a(n):
A) observational study.
B) nonrandomized experiment.
C) completely randomized experiment.
D) randomized block design.
E) matched pairs design.

Question

Quizplus · Accepted Answer

This is an observational study because the professor is merely observing the outcomes (jury scores) of students who choose to attend the extra sessions versus those who do not, without manipulating any variables or assigning students to groups himself.

A Music Professor Offers His 40 Students the Option of Coming