3.1　Analytical framework of coherence construction in multimodal discourses

The basic assumption underlying the task of framework establishment in this chapter is the social semiotic theory which regards all semiotic modes，such as verbal language，images and gestures，as parallel means of expression serving to realize a higher-order semantic unit.The concept of coherence should cover the connectivity among all semiotic resources in the text，no matter which mode they are presented in.It is assumed that the insights from coherence studies in linguistic texts may also be useful in accounting for the construction of coherence in multimodal texts which involve semiotic modes other than language.Therefore this section will start from the conclusions drawn from the review of coherence theories in Section 2.1.The major argument is that global coherence，local coherence and cohesive devices can form a framework that allows systematic analysis of coherence construction.The justification for this argument will be provided in Subsection 3.1.1.Sub-section 3.1.2 will discuss the possibility of extending this framework from purely linguistic sense to multimodal sense in order to analyze the coherence construction in the multimodal English learning advertisements.The commonalities and distinctions in the verbal mode and visual mode will be prudently considered to make sure that appropriate adaptations be made to the framework.In Sub-section 3.1.3 the framework for analyzing coherence construction in multimodal discourses will be presented，with the adapted definitions and criteria of global coherence，local coherence and surface cohesion.The relationship between the three levels of coherence will also be discussed.