Often they will say whether it is chopped or not.
1/2 cup nuts, chopped coarsely = measure the nuts, then chop
1/2 cup chopped nuts = chop the nuts, then measure them
That's the way that I see it. However, I think the best thing is to try to do the measurement, but don't stress over every bite. That will discourage you. The best thing about measurement is that it will help you become aware of what you eat.