2024 Volume 65 Issue 1 Pages 73-92
In this study, a cluster analysis was conducted on all the observations and experiments in the lower secondary school science textbooks of Company X and Company Z, which were approved by the Ministry of Education in Japan in 2020. The purpose of the cluster analysis was to clarify the exploratory characteristics of each group, which were derived by classifying them based on the trend in the content rate of “skills of inquiry” developed by Hasegawa et al. (2013). Comparisons were also made among the textbooks published by three companies, including Company Y, which was analyzed and interpreted by Yamada et al. (2021). The results of our analysis revealed the following. (1) Observations and Experiments in the lower secondary school science textbooks published by “Company X” and “Company Z”, which were approved by MEXT in 2020, could be classified by the tendency of “skills of inquiry into five or six categories, respectively. (2) Based on the exploratory characteristics of each cluster of the “Company X” and “Company Z” textbooks, we were able to clarify the characteristics of each grade level by analyzing and interpreting the trends of observations and experiments within each respective grade level. (3) Comparisons among the three companies revealed that the science textbooks published by “Company X” and “Company Z” showed significantly higher “hypothesis setting” tendencies than those of “Company Y”.
