Stack Exchange is a good example of these two methods of gamification:
I am curious as to whether there has ever been any research done that defines and contrasts these methods? I am specifically interested in discovering what sort of goals and behaviors collecting achievements encourage as opposed to collecting points. How do end-users respond differently to these methods? Or do they?
Taking Stack Exchange as an example, we could ask what sort of behaviors are we attempting to encourage with reputation as opposed to badges that require them to be separate entities?