Dr. Gowen decides to conduct the above study and see if spen…

Dr. Gowen decides to conduct the above study and see if spending time on TikTok decreases students’ overall grades. From her general psychology class, she records students’ overall grades. Then, she assigns students to two groups. Group 1 will watch TikTok videos every day for 30 minutes; Group 2 will not watch TikTok videos at all. The study will continue for 1 month. At the end, she will again record students’ overall grades. In the above study, what is the independent variable?