Best practices in measuring vowel merger

Vowel mergers are some of the most well-studied sound change phenomena. Yet the methods for assessing and characterizing an individual speaker's participation in an ongoing merger (or split) vary widely, especially among researchers analyzing naturalistic corpora. We consider four methodological approaches to representing and assessing vowel difference: Euclidean distances, mixed effects regression modeling (Nycz 2013), the Pillai-Bartlett trace (Hay, Warren, COT and CAUGHT among Canadians in the New York City region; and TRAP and BATH among Scots who work in Southern England. We conclude with some practical recommendations.