B.The use of multiple modal devices mirrors an interpersonal system of choices related to discourse strategies, and can reflect generic expectancy (cf.Martin, 1992; Martin, 2000/2006; Fries, 2002）;
C.A language-based approach to cognition is feasible (Halliday & Matthiessen, 1999; White, 2005/2006; also cf.Jackendoff, 1997).
This dissertation conducts an empirical study of MSAs as a means of modality supplementing in discourse through four corpora: PS, JI, AW, and LR.Different types of data concerning the use of MSAs will be shown, such as:
(A）the central MVs that MSAs tend to co-occur with;
(B）the semantic categories that the MSAs belong to;
(C）the functions of the MSAs;
(D）the discrepancies of the distributions of MSAs in relation to genre.
In each situation of data revelation, genre and other contextual factors as well as interpersonal meanings are the focuses around which the analysis concerned will be conducted.The corpora analysis aims at testing the qualitative method adopted in this dissertation and the functions of modality supplementing that MSAs perform.
1.4 Data collection
Data analysis is important for linguistic assumptions and attesting.To convince the readers of the existence, types, forms and functions of MSAs as a means of modality supplementing, this dissertation chooses the genres that are rich in modality: PS, JI, AW and LR.In fact, the writer of this dissertation has the corpus of ICE (International Corpus of English）at hand; nevertheless, he does not think it appropriate for his study of MSAs and modality supplementing though it could serve as a reference in his research to a certain extent.
In this study, the corpus of PS consists of 60 articles, each article amounting to about 3,000 words on average and the total being around 180,000 words.The corpus (70 articles, about 170,000 words）of JI contains three parts: interviews with political leaders (20 articles, about 60,000 words), professional artists (30 articles, about 60,000 words）and ordinary citizens (20 articles, about 50,000 words).The corpus of AW contains 40 articles (about 175,000 words), of which social sciences and humanities outnumber natural sciences by 65% to 35%.The corpus of LR amounts to 178,000 words.The four corpora that are established for the current study can be summarized as Table 1.1:
As can be found from Table 1.1, a basic principle for the establishment of the corpora is equal size.In other words, the four corpora are basically the same size, with only a margin of difference.The number of articles varies from corpus to corpus because of the nature of genres.For instance, research articles are normally longer than public speeches, for in the former case the writers concerned generally have to cover the stages of introduction, literature review, method, corpus, result, discussion and conclusion, whereas in public speeches speakers just need to express their own views on the topics involved so as to lead the audience in a certain direction, and long public speeches are not widely accepted.In comparison, laws and regulations can be much longer than either public speeches or research articles; a law could cover many areas and points, and take many pages.
The public speeches are downloaded from the Internet.The study chose the data from the website of, which is a bank of American public speeches.This corpus covers a wide range of topics such as politics, morality, education and sports.
The journalistic interviews are downloaded from the Internet and extracted from magazines.The data are from the websites of, which is a bank of interviews with Margaret Thatcher, the former British prime minister, which are concerned with such topics as politics, arts, and routine life, and the magazines of Newsweek (1996-2006）and Time (1996-2006).
The academic writings come from the Internet, journals and linguistic monographs.This corpus covers topics such as linguistics, economics, environmental protection and math.In terms of the Internet, the study used data from and www.grammatics.com/appraisal.The journals selected for studies include Advances in Applied Business Strategy (1998-2005), Advances in Financial Economics (2000-2003), Advances in Inorganic Chemistry (2000-2002), Advances in Mathematics (2000-2002), Agricultural Economics (2002-2005), Applied Energy (2002-2005), Journal of Applied Linguistics (1989-2006), Journal of English for Academic Purposes (1995-2006), and Journal of Pragmatics (1994-2006).The linguistic monographs that are used as data include such works as Linguistic Semantics: An Introduction (Lyons, 1995), Pragmatics (Levinson, 1983), Foundations of Cognitive Grammar (Langacker, 1987/1991）and An Introduction to Functional Grammar (Halliday, 1994).
