Dr. Cohen and her colleagues wanted to test the effect of a new app called Habit Tally, designed to help a person form new habits on weight loss. A sample of people needing to lose 100 lbs or more were selected for the study. Participants were all weighed at the beginning of the study and then were randomly assigned to either use Habit Tally for 3 months or use the already established Weight Watchers app for 3 months.. After the 3 months, participants were weighed again. Results showed that participants lost the same amount of weight, on average, whether they used Habit Tally or the Weight Watchers app. In this study, the independent variable (IV) is the .