抄録
This paper presents a new arrangement for cultivating pupils' ability in metacognition in the science classroom. This arrangement assures pupils of more than a single opportunity to conjecture what will happen next in their experiment, whereas conventional arrangements provide pupils a single opportunity only. In the new arrangement pupils can revise their conjectures at each opportunity. Their revision helps them to conduct their epistemological reflection on changes in their thoughts if the revision is objectified. At the same time, the new arrangement makes it easier for the teacher to realize pupils' change in thoughts about the experiment when pupils obtain new findings from their observations. In addition, teachers should take into consideration that pupils obtain such findings from discussions, or sometimes chats, with other classmates. Pupils' new findings naturally lead them to change their conjectures on the basis of these findings. If the teacher gives proper advice, pupils will recall the reasons for their change in thoughts. This means that the advice stimulates pupils to conduct epistemological reflection on their thoughts. Examples of such pieces of advice are also given.