日本語を母語とする児童・生徒に対する文章の難易度調整に関する考察 : 『毎日小学生新聞』を一例として

This study quantitatively analyzed articles from the Mainichi Shogakusei Shimbun (Mainichi Elementary School Newspaper, MEN) and the Mainichi Shimbun (Mainichi Newspaper, MN) to identify characteristics of language adjustment, particularly difficulty adjustment, in written texts for Japanese native-speaking children. Text difficulty was evaluated using two readability systems: "Readability Research Lab" and "jReadability". Results revealed differences in character and word types, with MEN exhibiting lower text difficulty than MN. However, both readability scores for MEN indicated a text difficulty level equivalent to that of high school students. In terms of parts of speech, nouns displayed the largest difference in proportion among content words, with MEN having a 2.8-point lower proportion than MN. Nevertheless, the difference in noun density per sentence was not significant enough to suggest a change in genre or target readership. The noun density in MEN was comparable to that of texts requiring a certain level of specialization. Furthermore, using the "Japanese Language Education Vocabulary List Ver 1.0," lexical difficulty in the texts was assessed. Results showed that MEN contained a higher proportion of beginner-level words and a lower proportion of intermediate-level and above words than MN, indicating lower lexical difficulty in MEN. This tendency was more pronounced in articles with topics not shared by both newspapers, suggesting that topic selection for children may have contributed to the lower lexical difficulty.