Staff turnover is always a concern in schools and the Instructional Coordinator position, specifically, should be someone who is trusted and has established strong relationships with teachers in the building. It is hard for Instructional Coordinators to have much influence and impact when there is a new person in the position each year or few years. The interviewer is concerned with finding a long-term fit for this role. Your objective here is to remove any doubts that your career trajectory will lead you away from the education field. Be sure to communicate your commitment to the role, without making any promises you know you can't keep.