Examination of phonetic data can show when phonologization has or has not occurred. Under the general Economy assumption of generative linguistics, this is important for theoretical phonology, since only cases where it has occurred require a phonological account. A modular view of phonetics and phonology is assumed, as it is clearly consistent with generative theory. A procedure for acoustic phonetic testing for phonologization is illustrated using data from one speaker of Palestinian Arabic and one speaker of Stát'imcets Salish. The testing can confirm phonological accounts or cause their revision. How it can cause revision is illustrated with the Stát'imcets data: the speaker's retraction harmony affects a rightward vowel, which is unexpected from standard descriptions of the harmony in that language. The testing can also identify cases of phonetics-within-language. This is illustrated with the St'at'imcets speaker's schwa lowering.
