Abstract
In this study, we use Balanced Corpus of Contemporary Written Japanese with annotations of predicate-argument structures to quantify word order freedom, case marking richness, and the correlation between the two in six text genres. The results of the study clarified the following three findings. Firstly, it was found that the word order freedom tended to increase in the order of white papers, Yahoo! Blogs, Yahoo! Chiebukuro, newspapers, magazines and books. Secondly, it was clarified that the case marking richness increases in the order of Yahoo! Blogs, Yahoo! Chiebukuro, newspapers, magazines, books and white papers. Thirdly, it was revealed that a positive correlation was found between word order freedom and case marking richness in five text genres other than white papers. This research is the first to quantitatively analyze the relationship between word order freedom and case marking richness in Japanese. The results of this study will be useful for a deeper understanding of Japanese in terms of the relationship between syntax and morphology, and in terms of language universals.