Advice on rating system

Hi,
I'm doing a simple rating system, but I need and advice on the
controllers. My system rates article.

Should I add an action rate in the article controller or should I create
a rate controller and add the action create?
What's the cleanest way?

Greg

What models and relationships do you have? I ask because it is not
clear whether a rating is just an attribute of an article or whether
an article has many ratings, so that a Rating is a model in it's own
right.

Colin