The Effect of Backchannel Utterances as a Strategy to Facilitate Idea Generation in a Copresence Situation: Relationship to Thinking Tasks

This study investigated the effect of backchannel utterances (BU) as a strategy to facilitate idea generation when a listener was copresent with a speaker who was engaged in idea generation. Twenty-four female undergraduate students participated in the main experiment, which used a think-aloud method. Independent variables were frequency of BU from listeners, and the task category of idea generation (prediction and resolution). Dependent variables were the number of ideas generated, speaking time, motivation of speakers, and speakers’ perception of listeners’ interest in, agreement with, and admiration of speakers’ ideas. The main results of 2 × 2 (frequency of BU × task category) ANOVAs were as follows: 1) The main effect of BU was significant for all dependent variables. 2) The interaction between the two factors was significant only for the number of ideas generated, that is, the effect of BU was larger for 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 BU inhibited idea generation. The present findings showed the effectiveness of BU as a strategy for facilitating idea generation. The interaction of BU and task category was interpreted in terms of the possibility that the two kinds of tasks involved different thinking processes. Because the interaction was found only for idea generation, it was suggested that BU had two influencing pathways: one facilitated positive social cognition and motivation, which led to speaking more, and the other activated idea generation itself.