The purpose of our research is to clarify students' aspects of changes in lesson practices based on 'Abduction', focussing on their speech activities for framing a hypothesis and verifying it. For that purpose, we gave lessons to 57 students of the 5th grade (two classes) in the Kobe municipal K elementary school. We considered that the teacher allowed himself to speak as only a little as possible and students weren't shy of expressing their opinions. Also we subdivided the work sheet into 5 parts of the work sheet (1), (2), (3), (4), (5), designing to clear students' aspects of changes. After lesson practices, we evaluated their descriptions quantitatively and carried out the analysis of variance for one factor and four levels (the repeated -measures design) and multiple comparison tests, so that we found great effects of their speech activities between the work sheet (3) and the work sheet (4). Then we gave attention to their wrong descriptions at the work sheet (1) and (3). From the viewpoint of their protocols of reactions to their wrong opinions on the video, we could capture their aspects of qualitative changes.