Abstract
This study investigated the effect of backchannel utterances as a strategy to facilitate idea-generation when a listener was copresent with a speaker who was engaged in divergent thinking. Twenty-four female undergraduate students participated in the main experiment which used a think-aloud method. Independent variables were frequency of backchannel utterances from listeners, and the task category of divergent thinking ( prediction and resolution ). Dependent variables are the number of ideas generated , speaking time, motivation of speakers, and speakers' cognition of listeners' interest in, agreement with, and praise of speakers' ideas. The main results of 2 x 2 ( frequency of backchannel utterances x task category ) ANOVAs were as follows: (1)The main effect of backchannel utterances was significant in all the dependent variables. (2)The interaction between the two factors was significant only in the number of ideas generated, that is, the effect of backchannel utterances was larger in the prediction task. An additional experiment was conducted to obtain a baseline of the number of ideas generated. Twelve female undergraduates engaged in the same tasks in the main experiment without listeners. The performance level was close to that of the low frequency condition. This result eliminated the possibility that low frequency of backchannel utterances inhibited idea-generation. The present findings showed the effectiveness of backchannel utterances as a strategy for facilitating idea-generation. The interaction of backchannel utterances and the task category was interpreted in terms of the possibility that the two kinds of tasks had different thinking processes. Through the fact that the interaction was found only in idea-generation, it was suggested that backchannel utterances had two influencing pathways; one was facilitating positive social cognition and motivation which led to speaking more, and the other was activating idea-generation itself.
