In business education, students might examine the impact of tourism on the local, regional, or world economy.[3] An interdisciplinary unit on rivers is appropriate for elementary or middle school Language Arts, Science and Social Studies. The local river system would be the unifying idea, but the English teacher would link it to Language Arts by studying river vocabulary and teaching students how to do a research report. The science teacher might teach children about the life systems that exist in the river, while the Social Studies teacher might help students research the local history and peoples who used the river for food and transport.