Smoothing the frequency of grammatical items in junior high school English textbooks and patterning them by fitting a model Professor Yasuma Kazuo, Faculty of International Liberal Arts, Dokkyo University
Contrary to the discussion on the first appearance of grammar items in the MEXT-certified junior high school English textbooks, there is almost no research material on the frequency of appearance, especially the frequency of re-presentation after introduction, which has a large influence on the learning effect. In this study, 40 grammar items were counted over the three years of junior high school, and the frequency of appearance for each unit was treated as a cumulative frequency to smooth out the random factors caused by arbitrary appearance. Next, the study time and the maximum cumulative frequency were standardized, and a cubic function was applied to the cumulative frequency data, resulting in a model with an accuracy of 0.937 to 0.975 squared residuals. A factor analysis was performed by considering the coefficients of the function used in this case (intercept, linear term, quadratic term, and cubic term) as variables, and it was found that there are two trends in the grammar items: convex distribution and concave distribution. Items with a convex distribution are presented in large numbers in the assignments at the time of introduction, but there are few opportunities to study them after that, so they may not be retained well. On the other hand, concave distribution includes many basic items that are introduced early and have a high frequency. If these are well understood at the beginning, the application effect will increase as the learning progresses, but if they are left insufficiently understood, it may lead to incomplete retention and even a decrease in motivation. Furthermore, it was observed that there are many items with large fluctuations in the second year of junior high school.
