Graphic Organizers should be introduced during the Activating Strategy of the lesson to build or activate prior knowledge. This gives students a framework for beginning to think about the new content and connect to what they already know.
For example, during the Activating Strategy of a lesson on different music styles, this teacher presented this graphic organizer depicting the relationship among the different styles students would be expected to learn about. He then had students brainstorm what they already knew about different styles and identify ones they were not familiar with.