A Systemic-Functional Exploration Of Evidentiality In The EST Discourses

As a pervasively-existing linguistic phenomenon,evidentiality is broadly referred to as the speaker/writer's indications of information source provided in the proposition in verbal communication and attitudinal expressions committing to the degrees of reliability and objectivity.In today's research field of evidentiality,combining the concept of "evidentiality"with Discourse Analysis(henceforth DA)under the theoretical supports of Systemic-Functional Linguistics(henceforth SFL)has been proven as an effective means used consistently(Hu,1994b,1995;Tang,2007;Yang,2009;Yang&Xie,2014;Lv,2015;Yu,2015;Zhang,2016,etc.).However,Halliday,the forefather of SFL,has never himself dealt with evidentiality as an independent grammatical category in any particular chapter in Systemic-Functional Grammar and it is mentioned only in some limited contents in his An Introduction to Functional Grammar(Halliday&Matthiessen,2008/2012).Thereby,it is believed that there is a large amount of issues in need of being further supplemented and improved when analyzing evidentiality under the theoretical guidance of SFL.For instance,the explorations of relation between evidentiality and genre or sub-types of a genre in which evidentiality as a linguistic strategy is adopted.For the data collection,this research chooses the discourses from English of Science&Technology(henceforth EST),which has two sub-genres,i.e.English of Specialized Science&Technology(henceforth ESST)and English of Common Science&Technology(henceforth ESST).In constructing a small-scale corpus,this study altogether collects 60 discourses from the EST genre.Specifically,this EST corpus is composed of two corpora,i.e.ESST corpus,in which 20 research articles related to different disciplines(i.e.natural science and social science)are selected randomly from the core academic journals worldwide,and ECST corpus,in which 40 articles are chosen randomly from the world-renowned magazines about popular science.The equivalence of word number is set as the criterion for the comparative part between these corpora whose total word numbers are very close to each other(i.e.ESST:112,476 words;ECST:115,455.words).In these two sub-genres,there is the in-between comparability that can be therefore reached.For the theoretical foundation,this study selects SFL systems such as Modality system proposed by M.A.K.Halliday and Appraisal system formulated by J.R.Martin collectively to be its analytical framework,aiming at lexicogrammatically describing and semantically interpreting evidentiality adopted in the discourses from EST genre and its sub-genres as ESST and ECST.Specifically,there are four concrete research objectives to be reached:(1)To lexicogrammatically describe the realization patterns,distribution features,frequencies of occurrence and preferences of the authors' evidential choices in EST discourses;(2)To semantically interpret the features of modal meaning in evidentiality in EST discourses:How do the authors' evidential choices take explicitly or avoid implicitly the different-degreed modal responsibility?How do the other external information sources take the modal responsibility substituting the authorship?(3)To semantically interpret the features of evaluative meaning(i.e.that of heteroglossic engagement)in evidentiality in EST discourses:How are the writers' evidential choices distributed semantically into different dialogic resources?What kind of backgrounded motivations drive the EST authors to make evidential choices as such?(4)To reveal the differentiation of evidential choices in ESST and ECST lexicogrammatically and semantically/functionally and to explain what backgrounded intentions set stage for these differences.For the methodology,this exploration adopts the hybrid research method combining the quantitative and qualitative,"the unbalanced/sequential mixed design" in particular.Within this design,this thesis,in general,prefers holding that the quantitative research is dominant to the final conclusion of the whole and the qualitative analysis serves as an interpretative reinforcement to the quantitive results.Through this study,we have found that the following factors propel the EST authors to make some certain evidential choices:(1)at the lexicogrammatical stratum,evidentiality functions as a way of constructing scientific knowledge,i.e.scientific knowledge is constructed in the discourses by means of "reporting","belief","sensory" and "inferring";(2)at the semantic stratum,evidentiality functions as a means of objectifying the scientific knowledge,i.e.objectification of knowledge in EST discourses is reached by two major means:taking or avoiding the modal responsibility consciously and manipulating the dialogic space purposefully;(3)in terms of comparison,series of distinctiveness between ESST and ECST are discovered in their differentiations regarding the knowledge construction and objectification,and these differences,to some extent,lead to the internal differences within EST genre;(4)the distinctions between ESST and ECST in their communicative purposes and target readers apparently give rise to the authors' different orientation when choosing evidentials to produce,express and communicate different meanings at the semantic stratum.The relation between EST genre and evidentiality can thus be believed as a dynamic realization and a co-evolving relation,in which every evidential choice is one of the specific realization of the generic features.These above-given findings,theoretically,have further developed the traditional research pattern of evidentiality,not only by unfolding the lexicogrammatical and the interpersonally-functional nature of evidentiality but also closely probing into this linguistic phenomenon in the cross-genre or multi-generic comparison.Moreover,this study,by working out the semantic/functional features in discourses from EST sub-genres(i.e.ESST and ECST)and the relation between evidentiality and the genre where it is occurred,broadens the research scope of evidentiality.Furthermore,by applying SFL as the theoretical framework,this thesis re-verifies the cogency and powerfulness in its theorization and wide-ranging appli ability.Practically,by comparing the lexicogrammatical and interpersonally-functional features of evidentiality in discourses from the sub-genres of EST,this thesis poses a strongly positive influence upon bettering the reading,writing,and even teaching of scientific languages.What is more,it proves that evidentiality can be unproblematically accounted as a reasonable standard of differentiating and grading ESST and ECST in the world of scientific languages.