A teacher wants to know if burning a scented candle affects students’ performance on pop quizzes. In the experiment, there will be a treatment group and a control group each taking their quizzes in a room that either does or does not have a scented candle burning. On a randomly chosen day, the first 15 students who arrive to class will be the control group while the last 15 students who arrive will be the treatment group.
Answer
A
The characteristics of the two groups should be roughly equivalent because both groups have 15 students.
B
The characteristics of the two groups should be roughly equivalent because the students were split into groups on a randomly chosen day.
C
The characteristics of the two groups might not be roughly equivalent because the students were not labeled and given a random number to place them in one of the groups.
D
The characteristics of the two groups might not be roughly equivalent because students who arrive around the same time might be friends and have similar preferences for scented candles.