we're on the same page. they understand that the internship lasts a set timeframe. during the fall/spring, it's just an externship to help them boost their resumes. during the summer, they know it ends when they go back to school.
i did a terrible job conveying it earlier, but i am very clear about the expectations up front when i originally sit down with the prospective interns to see if it's a good fit for both parties.