Figures of Thought: The Use of Diagrams in Teaching Sociology.

College teaching is most often practiced in the form of talk. Instruction as talk can be likened to the activity of taking apart a castle, stone by stone, and shipping it from Europe for reassembly in America. In this simile the castle represents a set of ideas or concepts, simple or complex, which reside in the mind of the instructor. This conceptual knowledge is broken down, packaged in small, intricate verbal containers for shipment to the New World of the student's mind in hortatory, wind-powered vessels known as lectures. In this process one major difficulty stands out. While the disassembler-the instructor-sees in the mind's eye how the finished castle looks, understands its floor plan, rummages comfortably in its ancient rooms, and knows in what sequence the pieces are best shipped, the reassemblers-the students-know none of this. If they did, instruction would be redundant. A central challenge and dilemma of teaching is to provide students with the intellectual blueprints for assembling a