I am conducting an experiment regarding review for exams and have concluded that students who accessed an online video review score much higher on an examination.
Are there rival causes which could as well describe why students who accessed the video review scored higher on the exam than students that didn't access it? How could each rival cause describe the video review-exam score relationship?
If I want to enhance this experiment what procedures would you propose that would help isolate the effect of video review on exam scores and explain why?