Mapping japanese dialects

The first Japanese dialectological atlas was published at the beginning of 20th century, but at that time methodology was not established enough. Kagyuukoo published on 1930 is characterized by its correspondence method. On the middle of 20th century geolinguistic survey was conducted at Itoigawa area. The purpose and the method of geolinguistics were first proposed by this research. At the same time, National Institute for Japanese Language investigated all over Japan, and edited Linguistic Atlas of Japan (LAJ) and Grammar Atlas of Japanese Dialects (GAJ). Since LAJ and GAJ inspired research activities in Japanese geolinguistics, more than 400 linguistic atlases have been published in Japanese dialectology. 100-year history of Japanese geolinguistics has revealed that dialectal data include both linguistic information and geographical information, which must include the spatial data. Mapping itself is an outcome of the examination to each hypothesis, and it would lead to model the geographical information.