本研究探討國小學童水的三態相關解題策略與概念。採質的研究法，主要運用放聲式思考晤談，並輔以問卷、教學錄影帶、活動記錄單等方式。研究對象為201 位國小四年級學童，經由前測問卷與晤談兩方式，篩選出具有水的三態另有概念的學童共28 人，進行問題解決教學活動，教學後再進行一對一晤談，以了解學童解題時所運用的概念類型，以及解題的策略。研究結果顯示：
一、學童的解題概念類型，是由低層次到高層次分佈，依序為：具體概念層次、
半抽象概念層次、抽象概念層次。二、 學童的解題概念發展型態可歸納為：(1)以較高層次的概念來發展解題思考，並且概念呈現穩定的狀態。(2)在同儕互動下，原先使用較低概念層次的學童，改變為使用較高層次的概念。(3)教學後單獨解題時，因為缺乏小組互動的機會，兒童有可能重新使用較低層次的概念。三、在解題策略方面可歸納如下：(1)教學前具有相同概念並不代表會有相同的解題策略形式。(2)學童所思考的概念會影響其解題策略形式。

problem-solving teaching activity and then a one-to-one interview. The results of the study were as follows:
(1)There were three levels of problem-solving conceptions that the students had: the concrete level of conceptions, the half-abstract level of conceptions, and the abstract level of conceptions, (2)The style of conceptual development in problem-solving that the students had was mainly using higher level conceptions to solve problems stably. Furthermore, through peer discussion and reflection during the problem-solving activities, students who used the lower level conceptions previously could use the higher level conceptions. However, after teaching, some students without peer interaction would possibly use the lower level conceptions again, and (3)We also found that students who had similar preconceptions might not apply similar problem-solving strategies. However, the conceptions that students used
influenced the strategies the students used in problem-solving.