5. whenever adrian plays his favorite video game, he always gets a higher score if he plays
while listening to music. he wants to know if listening to music while playing video games
affects other kids as well. he decides to test all the boys in his class. what should adrian do
to avoid experimental bias?
o only test the boys who usually play video games
o only test the boys who like video games
o include girls in the experiment
o include the teacher in the experiment