An experiment to measure learning when stimuli are presented through one or two channels showed that an auditory signal combined with a relevant picture--the two-channel cue summation condition--was superior to five other methods of communication, or "treatments." These other five were: one-channel visual only; one-channel auditory only; two-channel redundant, i.e., words presented audibly with simultaneous presentation of the same words visually; two-channel high similarity, i.e., two words presented audibly with simultaneous presentation of pictures of different objects of the same class; and two-channel low similarity, i.e., words presented audibly with simultaneous presentation of pictures of objects of a different class. Almost 250 seventh graders were stratified for intelligence and randomly assigned to the six treatments. Each treatment consisted of a stimulus series of 15 nouns, followed by 40 items from which the respondent had to select the original items. Statistical tests showed the cue summation condition to be superior to the redundant condition and the visual only condition to be superior to the auditory only condition. No other significant differe ces were found. (OH)