This Recommendation describes a method for quantifying the amount of information that multiple interlocutors correctly exchange over a system. The measure serves to assess the effectiveness of a voice communication system by comparing the amount of correct information exchanged over the system relative to the amount of correct information these interlocutors achieve in face-to-face communication. This metric qualitatively evaluates a multiparty conferencing system's ability to transmit multiple voices and maintain their independence. The method has demonstrated sensitivity to system parameters including duplex capability, spatialization, bandwidth and delay.

The method described herein applies only to voice communication; audiovisual communications is not covered by the scope of this Recommendation. The method does not include the measurement of technical properties of the systems.