This survey describes 15 systems that provide feedback to students. Feedback is defined as information transfer from the instructional material to the student after a response is made by the student. The feedback is directed primarily to the student, but when a permanent record of the response occurs this information is also available to the instructor. Each system is reviewed with respect to 1) state of development, 2) production process, 3) reversibility or irreversibility, 4) cost of production, and 5) legal implications. The systems discussed are 1) mimeograph with water soluble dyes and water pens, 2) spirit duplication and chemical pens, 3) xerography with an erasable overlay, 4) letterpress with water soluble dyes and pens, 5) letter press using latent images and chemical pens, 6) letterpress with a scrapeable overlay, 7) letterpress with overprinting which is eliminated by a plastic reader, 8) letterpress or offset using electrically conductive inks and an electrically activated feedback, 9) letterpress or offset with a pressure-sensitive chemical feedback, 10) letterpress with latent images and overlay printing, 11) letterpress with erasable overlay, 12) letterpress or offset with magnetically activated feedback, 13) letterpress or offset with fluorescent activation of feedback, 14) letterpress or offset using absorbent white ink on white, and 15) letterpress with prepunched response forms. (MBM)