Abstract
In 1998 astronomy classes were shifted from grade 7 to grade 9, as advanced spatial cognition is required to understand astronomy. Consequently, students don't learn astronomy from grade 5 to grade 8 because of this change. However, detailed data was insufficient to consider this impact on the spatial cognition of students. In this paper, we investigate the spatial cognition of students. Specifically, the relationship between the learning period of astronomy and understanding of two concepts: the left / right concept and the spherical concept. The major results of this study are as follows. (1) The hemispherical concept in 2007 is generally less well understood than in 1985 at between grade 5 and grade 8. (2) Understanding of the spherical concept does not go down, compared to understanding of the left/right concept after students learn it. (3) Spatial cognition has improved between grade 5 and grade 8 although they do not learn astronomy, so the other effects can be considered. (4) At grade 9, understanding of each concept of spatial cognition in 2007 is almost the same or better than that in 1985.
