Why would you do a report to see if Peaceful Protests worked or not?

Because it would be interesting to find out, for one. Changes have been brought about in recent history by peaceful protests (the Civil Rights Movement in the US) as well as by violent protests (Ukraine). You could - among other things - try and find out which kind was used when, and to what effect; whether there were underlying factors that made protests work by being peaceful or violent; and what kind of changes were the subject of violent and peaceful protest respectively. In short, you might learn something yourself.