Which statement best describes the composition of the groups?
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.
The characteristics of the two groups should be
roughly equivalent because both groups have 15
students.
O The characteristics of the two groups should be
roughly equivalent because the students were split
into groups on a randomly chosen day.
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.
O 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.