This study quantitatively analyzed the readability and vocabulary level distribution of 412 books of textbook data found in the “Balanced Corpus of Contemporary Written Japanese”. As a result of the analysis, the following 4 points became evident: 1) As the grade in school advanced, the text also becomes more difficult; 2) The 10 grades in school from grade 1 to senior high school are divisible into 5 groups; 3) Whereas “social studies” and “mathematics” and “science” are composed of comparatively difficult text, “Japanese” and “Arts” are composed of comparatively easy-to-read text; and 4) Whereas beginner"s vocabulary decreases as the grade in school advanced, the tendency has been for intermediate vocabulary to increase. These quantitative analytical findings are thought to be the basis for determining the scope of Japanese language instruction in the coursework of Japanese language education for young people.
This paper surveys the trends in the use of questionnaire surveys in dialectology and sociolinguistics in overseas countries based on Dollinger (2015). The method, in which a fieldworker asks a series of questions according to a questionnaire, has been utilized since the beginning of dialectology in Europe in the latter half of the 19th century, together with the fieldwork interview method, where the fieldworker has more leeway in eliciting responses. As the methods reached the U.S., the latter method became the primary choice for major dialectological projects like the LAUSC, while the former held a supplementary, second-rate position. The use of questionnaire surveys declined further when variationist sociolinguistics, which advocates the use of natural speech in linguistics, was born in and gained force since the 1970s. The questionnaire survey is still used in dialectological surveys in other countries, and a series of sociodialectological researches in Canada since the 1990s have brought it back to the forefront. I discuss three important issues concerning the method: the levels of linguistic phenomena suited to it, late adoption (Boberg 2004), and Regionality Index (Chambers and Heisler 1999).