A new method of dialect subgrouping
方言子分类的新方法
Hsin-I Hsieh 谢信一

Abstract 摘要
Traditional methods of subgrouping such as the tree method, the wave method, and the lexico-statistic method sometimes fail to apply, particularly when the material involves incomplete sound changes–changes that are still in progress or have terminated prematurely. The author proposes the diffusion overlapping method as a phono-laxico-statistic procedure of subgrouping to replace traditional methods where they do not apply or to supplement them where they do apply but the results need further confirmation. This method is based on a collorary of the concept of lexical gradualness in sound change: that the more phonological forms two or more dialects share with respect to a commonly initiated but independently executed sound change, the longer they must have developed together, and hence the more closely related they are.