Described is a device for use by teachers who are deaf, to assist them with the improvement of their instruction through the Flanders Interaction Analysis method of assessing teachers' classroom performance. Explained, and illustrated with photographs, is an electrical device which, when attached to a videotape recording camera, displays a 3-second visual signal on playback of a videotape--the signal corresponding to the audible "beep" ordinarily used with training materials for the Flanders system. (IM)