The Envelope of Variation in Multidimensional Register and Genre Analyses

While multidimensional analysis of register and genre variation is a very promising field, a number of problems with it have been identified. Of particular importance are the problems of eliminating grammatical sources of covariation, while still maintaining a set of variables that are faithful to earlier discussions in the literature. One potential solution to both problems is to use the notion of the envelope of variation, as established by variationist sociolinguistics, where grammatical features are counted not as a proportion of the total number of words, but as a proportion of the opportunities for these features to be produced. This technique is also valuable because it allows variables to be targeted with more precise algorithms.This paper describes a pilot study that integrates the envelope of variation into multidimensional analysis. It focuses on two variables (third-person pronouns and demonstrative adjectives) that we would not expect to covary according to Biber’s (1988) descriptions, but for which Biber himself found a significant correlation (-0.282). Using twelve texts from the MICASE corpus (96,000 words), the two variables were corrected based on definitions in the original literature and then restated as testable hypotheses with envelopes of variation. The correlation was -0.685 when using Biber’s original methods, - 0.505 when using corrected algorithms, and -.511 when using corrected algorithms with an envelope of variation. The first correlation was statistically significant, while the second and third were not. However, all three were higher than Biber’s original correlation, and would be significant if they were replicated with a corpus as big as Biber’s. The study emphasizes how complex the counting of any given variable is in corpus analysis, and how much work is necessary to properly identify each one.