Do students learn geometry better from an online course or in class with a teacher? To find out, a large high school set up an experiment with 500 student volunteers. The school randomly assigned
half of the students to take the geometry course online, watching videos to inform their learning. The
other half took a more traditional course with lectures by a teacher. The same teacher was used for both
courses, and both courses met for the same amount of time each day. At the end of the year, the success
of each program was measured by students’ scores on the geometry final exam, which was the same for
both courses.
a) Explain how this experiment used comparison.
b) Explain the purpose of randomly assigning the students to the two treatments.
c) Name two variables that were controlled in this experiment and why it was beneficial to control
these variables.