Dissertation - Michael Becker

(33) Differences between back and front stem-final vowels in the lexicon vs. thedifferences between back and front vowels in the experiment, by size and place.30%CVCVp25%20%human responsesCVkCVCt CVCkCVp15%10%5%-5%CVCVtCVCVkCVCVCV0%-20% -10% 0% 10% 20% 30% CVC 40% 50%-10%CVtCVCp-15%lexiconThe contrast between the strong correlation in (31) and the lack of correlation in (32-33) shows that speakers’ behavior is best understood as replicating the lexicon’s size andplace effects, but not replicating its height or backness effects. This contrast is seen in thestatistical analysis below.The results were analyzed with a mixed-effects logistic regression in R (R DevelopmentCore Team 2007) using the lmer() function of the LME4 package, with participant anditem as random effect variables. The fixed effect variables were the same ones used in theanalysis of the lexicon: size, place, high, back and round.An initial model was fitted to the data using only size and place as predictors. Addingtheir interaction to the model made a significant improvement (sequential ANOVA modelcomparison, χ 2 (6) = 50.58, p < .001). The improved model with the interaction term isgiven in (34). This model shows that labial place and CVCVC size are more conducive39