Some researchers want to compare meditation and exercise to see which is more effective for reducing
stress. They randomly selected 100 people who suffer from high stress to participate in the study. The
subjects will either be given a 10-week course in a meditation program or they will participate in a 10-
week exercise program. The researchers must decide how to assign the subjects to these programs.
One option would be random assignment of the subjects into the programs. Another option is to allow
each subject to choose a program.
Which of the following is the main advantage of randomly assigning subjects to one of the two
programs rather than allowing them to choose?