Measuring dialect di erences ∗

We measure varietal di erences in general, and di erences with respect to standard languages in particular ( dialectality , in Herrgen/Schmidt's sense) in order to systematize observations about dialect di erences, to make sense of exceptions, and to enable measurements based on randomly selected material, thus obviating issues of potential bias. Finally, measurements allow the characterization of abstract relations among language varieties. We illustrate some issues with simple techniques for categorical data introduced by Séguy and re ned by Goebl, viz., issues concerning frequency, irrelevant variation, and competing forms. We proceed to measuring pronunciation di erences, focusing on di erences in the pronunciation of the same words in di erent varieties. Caution is needed to isolate pronunciation di erences from di erences in in ectional morphology, sandhi, and intonation. We characterize the di erence between sound segments and develop a measure of the di erence between the sequences of those segments in words, including insertions, deletions, and swaps (epenthesis, elision and metathesis). Automating measurement techniques exposes the issue of validation, which lay largely unexamined in earlier dialectology. We propose to validate measurements based on the degree to which they correlate with dialect speakers' judgments of di erence, justi ed by the presumed function of linguistic variation, that of signaling provenance.