Revisiting raters' accent familiarity in speaking tests : Evidence that presentation mode interacts with accent familiarity to variably affect comprehensibility ratings

This controlled experimental study investigated the interaction of variables associated with rating the pronunciation component of high-stakes English-language-speaking tests such as IELTS and TOEFL iBT. One hundred experienced raters who were all either familiar or unfamiliar with Brazilian-accented English or Papua New Guinean Tok Pisin-accented English, respectively, were presented with speech samples in audio-only or audio-visual mode. Two-way ordinal regression with post hoc pairwise comparisons found that the presentation mode interacted significantly with accent familiarity to increase comprehensibility ratings (X2 = 88.005, df = 3, p < .0001), with presentation mode having a stronger effect in the interaction than accent familiarity (X2 = 59.328, df = 1, p < .0001). Based on odds ratios, raters were significantly more likely to score comprehensibility higher when the presentation mode was audio-visual (compared to audio-only) for both the unfamiliar (91% more likely) and familiar speakers (92.3% more likely). The results suggest that semi-direct speaking tests using audio- only or audio-visual modes of presentation should be evaluated through research to ascertain how accent familiarity and presentation mode interact to variably affect comprehensibility ratings. Such research may be beneficial to investigate the virtual modes of speaking test delivery that have emerged post- COVID-19. [Author abstract]