Research questions - IA and EE

What is the difference between an extended essay research question and an IA research question (RQ)? Of course, the first difference is that the IA proposal does not have to have an RQ. An aim is sufficient. But I know many of us feel that a question gives focus, and allows the student to check they have answered it at the end. However, we have noticed that some students are framing their IA question as if it was a "to what extent" question, and it is not. So, how do the IA and EE RQs differ?