I’ve always had class participation as 10% of the students’ grade. The main reason is that I want the class to be as interactive as possible; I don’t think many of them will “get it” by just listening to me and taking notes. And if they don’t get it, they won’t be able to practice at home; they’ll just bring back incomplete homework. So I try to engage the students deliberately; when I call on them, I call on the ones who don’t volunteer answers. If someone is struggling with an answer, I might call on another student to bail them out.
And one of my favorite things to do is to ask for a volunteer to work/answer a problem. If they get it right, they get to pick the classmate to answer the next one. And so on around the room. They like this a lot; I see a lot of paybacks where A called on B yesterday so B calls on A today, but it’s kept friendly. So I like the class participation part of the grade, but I don’t generally leave it up to the students; I’ll engage them and make them earn that 10%. With the way the electronic gradebook works, I don’t enter the class participation grade until the end of the quarter, so a borderline grade will often get a small boost at the end, which is nice.