The choice of seven dialects is from Lee and Ramsey 2000's The Korean Language, p. 311, with Yukjin marked separately as per p. 313. The distribution of Yukjin is based on a 1998 Institute of the Korean Language overview of Korean dialect groups.

There are some issues with Korean dialect divisions. For example, the toneless varieties of the Yeongdong dialect spoken on the coastline of Gangwon Province, between the Hamgyong and Gyeongsang dialect areas, is sometimes classified as central and sometimes as Gyeongsang. For the purposes of this map, the existence of a pitch accent was used as the principal isogloss for the Hamgyong and Gyeongsang dialects, per the 1998 Institute of the Korean Language overview.