Answer:
scientific
Step-by-step explanation:
The professor is using scientific approach to conduct her study or to experiment.
The professor wishes to research on the positive effects of her new teaching approach.
She will take two different approach and will take her 9:00 a.m. class to teach about her new teaching methods while his 10:00 a.m. class will deliver her normal conventional lecture classes. Thus the students will get the opportunity of choosing which tapes they wishes to view from the two options.
Thus this is a scientific method of conducting her experiment.