The foundation of variation analysis is its attempt to discover not individual occurrences, not even overall rates of occurrence, but patterns of variability in the body (or bodies) of material under investigation. To aid in the interpretation of these patterns there are a number of different lines of evidence which arise from the statistical modelling techniques of multivariate analysis.

THREE LINES OF EVIDENCE

There are three levels of evidence (Poplack and Tagliamonte 2001: 92, Tagliamonte 2002: 731) available for interpreting the results of variation analysis as performed by the step-up/step-down method of multiple regression: 1) statistical significance, i.e. Which factors are statistically significant at the .05 level and which are not? 2) relative strength, i.e. Which factor group is most significant (largest range) or least (smallest range)? 3) What is the order (from more to less) of factors within a linguistic feature (constraint hierarchy)? Finally, bringing in the interpretative component of variation analysis, 4) Does this order reflect the direction predicted by one or the other of the hypotheses being tested? Each of these bits of information can, and should, be used to build your argumentation about the linguistic variable.