Abstract
The purpose of this study was to design an intervention strategy which induces changes from naive theories regarding 'conservation of mass in a water solution' to scientific theories through collaborative discussion during observation and experimentation sessions of the dissolution of substances in a fifth-grade science class, and then to examine the effects. Results of a descriptive analysis of pre-post tests and interactive analysis of verbalization activity showed that: 1) the teacher's revoicing, which coordinates prediction, date and theory, generates transactive discussion in the direction of learning towards 'self-transforming modes'; 2) the teacher's revoicing, which clarifies inconsistencies among theories of members and then reformulates the theories, generates transactive discussion in the direction of learning towards 'other-transforming modes'. These findings suggested that transactive discussion in 1) and 2) causes cooperative construction of theories.