You have been hired to help elect a politician to office. You wish to know which form of advertising will result in the best outcome. You divide your participants into 3 groups, with 9 people in each group. Group one listens to positive ads only, group 2 listens to negative ads only and groups 3 listens to both positive and negative ads. You then record each person's response as a grade of between 0 to 100. What are/is your degree(s) of freedom?