Effect Of Linguistic Features On EFL Learners’ Public Speech Quality

Linguistic features have been widely used in text stylistic analysis.The linguistic features can be quantitatively measured to differentiate registers and genres of the texts and to analyze the correlation between linguistic features and text quality.Public speech is a special spoken language,and it has special features.This paper collects public speech videos and their scripts and evaluation scores.Coh-Metrix is used to calculate linguistic feature indices of the script texts,SPSS is used to calculate the correlation between the indices and the global scores of the speech,and Wordsmith is used to extract index lines to see how linguistic features are used in materials so as to explore the effect of linguistic features on public speech quality,compare them with the results on writing quality and find the unique linguistic features of public speech.The 76 videos and scripts of TED-style speeches were collected from the class of Public Speaking and Debating.A panel of three graders evaluated the public speech quality.They scored the topic,speakers’ manner,pronunciation,and global quality of the speech separately.Fifty-three samples were selected for analysis after controlling the variation of the three variables.The linguistic features of each script were extracted from the Coh-Metrix.The correlated factors between linguistic feature indices and the scores of the global quality of the speech were collected from correlation analyses with SPSS to investigate the effect of significantly correlated linguistic features and their effect on EFL learners’ public speech quality.Wordsmith is used to further explore the impact of the use of pronouns on public speech.The results show that twelve linguistic feature indices,which reflect the word frequency of advanced vocabulary,connectives,narrativity,the content structure,the use of pronouns,and modifiers,are significantly correlated with the public speech quality.The twelve linguistic feature indices indicate four different trends of effects on speech quality: positive nonlinear correlation,negative nonlinear correlation,positive linear correlation,and negative linear correlation.In particular,the mean number of syllables,the standard deviation of number of syllables,the mean number of left embedded words before main verbs,the mean number of modifiers per noun phrase,and Flesch-Kincaid Grade Level have a positive nonlinear correlation with public speech quality,Flesch Reading Ease,narrativity,temporal connectives incidence have a negative nonlinear negative with public speech quality;the adjective incidence has a positive linear correlation with public speech quality,pronoun incidence,mean CELEX for Log frequency incidence for all words,and mean CELEX for Log frequency incidence for content words have a negative linear correlation with public speech quality.The results indicate that public speeches focus on the richness of content rather than lexical richness.Moderate syntactic and grammatical complexity and text readability are key to public speeches.Compared with writing,public speeches of higher quality will use fewer infrequent words to construct the public speech content and share more new information,pay less attention to the syntactic structure and lexical richness,and emphasize fluency,connection,and content richness.The results indicate that public speech requires the depth of thought rather than depth of language.Therefore,when constructing the content of the public speech,speakers should pay attention to expressing rich content and transmitting more information in fluent and concise language.The findings are expected to provide a reference for public speaking and speech writing.