Hi! I have to suggest a method to use for a quantitative comparative method. The study is about mock elections in school and the effect they have political participation in adult life. (sorry about m

Hi! I have to suggest a method to use for a quantitative comparative method. The study is about  mock elections in school and the effect they have political participation in adult life. (sorry about my english but i still have to write in swedish so i just need help with the choice of method). I thought about Mill's method of agreement but doesn't that presume that the "result" is already known? I need to suggest some form of addition to an already existing case study about mock elections but it has to be quantitative, and I don't know the result of these mock elections.