Type of Speech: 
Definition: 

Content that is presented prior to learning and that can be used by students to organize and clarify new incoming information. The purpose is to build a bridge from prior knowledge to the new information that encourages the understanding, learning, and retention of the new concept.

Additional Information: 

By activating relevant prior knowledge, advance organizers also help students stay focused on the subject. An advance organizer can come in a variety of forms. It could be a brief, abstract prose passage based on the student’s existing knowledge, which serves as a transitional statement for new learning or a diagram that directs the student toward the main ideas and relationships in the new content.

For further explanation:
The CTER Program provides WikEd, which contains an informative entry on advance organizers that includes information about the history, applications, and types of advance organizers.