Last 5 evaluations

Hello,

I'm building an app that will be used to evaluate students by different courses.

When I make a new evaluation of a selected course, I want to be able to show the 5 previous evaluations of that course.

I suppose I would need a special scope-like method in my 'Student' model, named 'last5evals' that receives the course id. Then I can call this method in the evaluation view:

$evaluation->student->last5evals($course_id);

That would return an array like {'A','C','A','B','B') which I can show in the view.

Is that possible or it there another way to reach my goal?

Thank you!