A Contrastive Study Of Evidentiality In TED Speech Between Social Science And Natural Science

Evidentiality refers to the source of knowledge and the speaker’s attitude towards the reliability of knowledge.Research on evidentiality from the perspective of discourse has been taking an upward trend.This paper aims to compare and study evidentiality in the TED speech between social science and natural science.In doing the research,two corpora,namely,natural science corpus and social science corpus are built based on the 100 TED speeches,50 in each field,which are collected from TED speech website.Based on Hu’s classification of evidentials,this paper answers three questions: 1)What are the general features of the use of evidentials in TED English speeches in social science and natural science?(from the perspective of the frequency and distribution)2)What are the similarities and differences in the distribution and lexical realizations of each type of evidentials in TED English speeches in social science and natural science? 3)What are the possible reasons for the similarities and differences?The results show that,in terms of the total number of evidence elements,a large amount of evidentials is used in Ted English speeches,whether in social science or natural science;no remarkable discrepancy has been found in frequency of evidentials employed between social science and natural science corpora;and the overall trend of seven types of evidentials is the same,that is,in terms of number from the largest to the least,they are deduction evidentials > expectation evidentials > hearsay evidentials > induction evidentials > reliability evidentials > belief evidentials >verbal resource evidentials.Through the comparative analysis of the distribution and lexical realizations of each type of evidentials,we have the following findings:The percentages of belief evidentials are low in both corpora.The percentage and the lexical realizations of belief evidentials in natural science corpus are relatively lower than those in social science corpus.In natural science corpus,speakers prefer to use belief evidentials which present a kind of group’s view like “we think/ know/believe”.Deduction evidentials occupy the largest portion both in social science corpus and natural science corpus.However the percentage of deduction evidentials innatural science corpus is significantly higher than that in social science corpus.Induction evidentials also occupy a large portion in both corpora,but the percentage of induction evidentials in natural science corpus is significantly higher than that in social science corpus.Social science corpus has more sense evidentials and natural science corpus has more inferring evidentials.Hearsay evidentials occupy a large portion and have rich lexical realizations in both corpora.However,the percentage of hearsay evidentials in natural science corpus is significantly lower than that in social science corpus.The number of all the lexical realizations in natural science corpus is lower than that in social science corpus except two lexical realizations-“data” and“show”.Reliability evidentials take up a comparatively high percentage and have rich lexical realizations in both corpora,but the percentage of reliability evidentials in natural science corpus is slightly higher than that in social science corpus.In social science corpus,speakers use more high reliability evidentials.Verbal resource evidentials occupy a small portion in both corpora,but the percentage of verbal resource evidentials in natural science corpus is slightly higher than that in social science corpus.Among those verbal resource evidentials,the “about+number”evidential takes up a larger portion in natural science corpus than it does in social science corpus.Expectation evidentials occupy the largest portion both in social science corpus and natural science corpus and the number of expectation evidentials in the two corpora is almost same.Based on the similarities and differences,this paper explores the reasons for the similarities and differences.It concludes that the objectivity,logicality and artistry discourse features of the English speeches and the different discipline features are the possible reasons for the similarities and differences.These findings will bring enlightenment to the learning and teaching of English speeches in different disciplines.