Summary

This research project is being conducted jointly by dialect researchers all over Japan who are collecting and sharing data to clarify how the Japanese dialect distribution has developed. Japanese dialectology officially started detailed research on regional language differences and mapping the results based on the geolinguistic method more than 50 years ago. While the National Institute for Japanese Language and Linguistics published national maps in the "Linguistic Atlas of Japan" and the "Grammar Atlas of Japanese Dialects", a number of detailed regional maps have been created mainly at universities. The basic principle in explaining dialect distribution is the "dialect radiation theory", which assumes distribution spreading from the center. The problem is that the principle has not been sufficiently verified. Fortunately, research on dialect distribution has a long history in Japan, and distribution changes over time may be explained by clarifying the current distribution. The project goal is to pioneer dynamic research that will illuminate dialect distribution changes on the basis of concrete data.