Effects of the Explanatory Situation on Explainers’ Understanding:

Prior studies have suggested that, in explanatory situations, the presence of a listener facilitates an explainer ＇ s understanding. However, published research has not, as yet, examined characteristics of explanatory situations that may facilitate explainers ＇ understanding. The present study investigated influences of the purpose of the explanation and the listener ＇ s prior knowledge of the concept to be explained. University students were asked to read a passage about chi-square tests and then to explain that concept to a listener. The conditions that were compared were (a) a teaching condition, in which 16 students were asked to teach a concept to a listener who had no knowledge of the topic, and (b) a confirmation condition, in which 15 students were asked to explain the chi-square concept to a listener in order to confirm their own understanding of the concept. After the explanations, all the students completed comprehension tests. The results indicated that the comprehension test scores in the teaching condition were higher than those in the confirmation condition. Analysis of the protocols revealed that the number of interpretive explanations, i.e., explanations giving an interpretation of formulas and procedures, was correlated with the scores on the comprehension test. Furthermore, the participants in the teaching condition generated more interpretive explanations than the participants in the confirmation condition did. These results suggest that explanations that improve understanding of a concept are more likely to be generated when the purpose of the explanation is teaching than when the purpose is confirmation.