Abstract: A means for presenting individual instructions from a group of predetermined instructions in a random fashion is provided by a random word generator and a binary counter which cooperate to address a programmable read-only memory which sequentially provides character forming potentials to a plurality of fluorescent character display indicators so that each indicator receives the same character forming potentials at each step in the sequence in combination with a binary decoder responsive to the binary counter for enabling only one of the indicators for each step in the sequence.

Abstract: A pair of endless belts of different lengths are intermittently and simultaneously advanced in sequential steps to present first and second indicia behind a viewing window. Each of the indicia on one belt identifies a movable part of a person's body and each of the indicia on the other belt identifies a movement to be performed. The indicia on each belt include a plurality of legends identifying each body part or movement, respectively, but arranged randomly in series on the belts. A selectively operable control serves to vary the time interval between sequential steps.