Fundamental theoretical considerations strongly imply that the degree of diffusion of a sound field in a reverberation room can be satisfactorily defined only when the degree of averaging (over either space or frequency, or both), inherently present in whatever measurement is under consideration, is included explicitly in the definition. A relatively sophisticated computer program for generating analog sets of source/receiver response characterstics in a reverberation room has been devised. Results have been obtained relevant to the following situations and including the uniformity to be expected from different amounts of space or frequency averaging: fixed diffusers, moving diffusers, response characteristics for higher-order source distribution.