Patent US 4,576,579

This invention provides students with immediate feedback as to the correctness of their responses by closing switches at two different depths. A holding frame aligns six sheets in layers, one above another. Holes that are punched through some of the six sheets of material are all aligned on the same grid pattern. The top sheet is an instructional sheet that has response areas punched in it at the site of correct and incorrect answers. The second sheet down contains no holes, is elastic and electroconductive, and hides the depth of the underlying holes from the student. The third sheet down is non-conductive and has the entire grid of holes punched in it. The fourth sheet down is electroconductive, and has holes punched in it only at correct answer areas. The fifth sheet down is non-conductive and has holes punched in it only at correct answer areas. The sixth sheet down is non-conductive, but contains electroconductive inserts at all correct answer areas. Instructional sheets have all incorrect answers by response areas that are over shallow holes, and have all correct answers by response areas that are above deep holes. Electric circuits that indicate to the student when he has made a correct or incorrect selection are completed when the student uses a stylus to push the elastic electroconductive sheet to the bottom of the shallow or deep hole where this sheet contacts other electroconductive material.